I got this to work in 1080i output to the HDMI input on the TV. I used PowerStrip to get the Modelines for my TV with use with my nVidia FX5500 with DVI Output.

My xorg.conf file is below:

Section "ServerLayout"
Identifier "XFree86 Configured"
Screen 0 "Screen0" 0 0
InputDevice "Keyboard0" "CoreKeyboard"
InputDevice "USB Mouse" "CorePointer"
EndSection

Section "ServerFlags"
Option "AllowMouseOpenFail" "true"
EndSection

Section "Files"
RgbPath "/usr/share/X11/rgb"
ModulePath "/usr/lib/xorg/modules"
FontPath "/usr/share/fonts/X11/misc:unscaled"
FontPath "/usr/share/fonts/X11/75dpi:unscaled"
FontPath "/usr/share/fonts/X11/100dpi:unscaled"
FontPath "/usr/share/fonts/X11/Type1"
FontPath "/usr/share/fonts/X11/Speedo"
FontPath "/usr/share/fonts/X11/PEX"
# Additional fonts: Locale, Gimp, TTF...
FontPath "/usr/share/fonts/X11/cyrillic"
# FontPath "/usr/share/fonts/X11/latin2/75dpi"
# FontPath "/usr/share/fonts/X11/latin2/100dpi"
# True type and type1 fonts are also handled via xftlib, see /etc/X11/XftConfig!
FontPath "/var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueType"
FontPath "/usr/share/fonts/truetype"
FontPath "/usr/share/fonts/latex-ttf-fonts"
EndSection

Section "Module"
# Comments: see http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=346408
Load "dbe" # Double Buffering Extension, very important.
# Load "dri" # This shouldn't be available choice if user has selected driver vga, vesa or nv.
Load "glx" # GLX Extension.
Load "freetype" # Freetype fonts.
Load "type1" # Type 1 fonts
Load "record" # Developer extension, usually not needed
# Load "extmod" # This is okay, but if you look into "man xorg.conf" you'll find option NOT to
# include DGA extension with extmod, and for a good reason.. DGA causes instability as it
# access videoram without consulting X about it.
SubSection "extmod"
Option "omit xfree86-dga"
EndSubSection
# Load "speedo" # Speedo fonts, this module doesn't exist in Xorg 7.0.17
# The following are deprecated/unstable/unneeded in Xorg 7.0
# Load "ddc" # ddc probing of monitor, this should be never present, as it gets automatically
# loaded.
# Load "GLcore" # This should be never present, as it gets automatically loaded.
# Load "bitmap" # Should be never present, as it gets automatically loaded. This is a font
# module, and loading it in xorg.conf makes X try to load it twice.
EndSection

Section "InputDevice"
Identifier "Keyboard0"
Driver "kbd"
Option "CoreKeyboard"
Option "XkbRules" "xorg"
Option "XkbModel" "pc105"
Option "XkbLayout" "us"
EndSection

Section "InputDevice"
Identifier "Serial Mouse"
Driver "mouse"
Option "Protocol" "Microsoft"
Option "Device" "/dev/ttyS0"
Option "Emulate3Buttons" "true"
Option "Emulate3Timeout" "70"
Option "SendCoreEvents" "true"
EndSection

Section "InputDevice"
Identifier "PS/2 Mouse"
Driver "mouse"
Option "Protocol" "auto"
Option "ZAxisMapping" "4 5"
Option "Device" "/dev/psaux"
Option "Emulate3Buttons" "true"
Option "Emulate3Timeout" "70"
Option "SendCoreEvents" "true"
EndSection

Section "InputDevice"
Identifier "USB Mouse"
Driver "mouse"
Option "Device" "/dev/input/mice"
Option "SendCoreEvents" "true"
Option "Protocol" "IMPS/2"
Option "ZAxisMapping" "4 5"
Option "Buttons" "5"
EndSection

# Auto-generated by KNOPPIX mkxf86config

Section "Monitor"
Identifier "Monitor0"
Option "DPMS" "true"
Option "ConnectedMonitor" "DFP"
Option "TVStandard" "HD1080i"
Option "NoLogo" "1"
Option "TVOverScan" "0.8"
Option "UseEdidDpi" "FALSE"
Option "DPI" "100 x 100"
VendorName "Panasonic"
ModelName "TH-42PD25"
# Modelines for the Pansonic Plasma DFP
# 1920 x 1080i Output to the HDMI TV Input
ModeLine "1920x1080" 74.250 1920 2008 2052 2200 1080 1084 1094 1125 interlace +hsync +vsync
# 1440 x 480i Output to HDMI TV Input
ModeLine "1440x480" 27.000 1440 1478 1602 1716 480 488 494 524 interlace -hsync -vsync
# 720 x 480p Output to HDMI TV Input
ModeLine "720x480" 27.000 720 736 798 858 480 489 495 525 -hsync -vsync
EndSection

Section "Device"
Option "sw_cursor"
Option "RenderAccel" "True"
Option "BackingStore" "True"
Option "MetaModes" "1920x1080" #if you're using 1080i or 1080p
Option "ModeValidation" "AllowNon60HzDFPModes, NoVertRefreshCheck, NoEdidMaxPClkCheck, NoHorizSyncCheck"
Option "UseEdidDPI" "False"
Option "XvmcUsesTextures" "True"
Identifier "Card0"
Driver "nvidia"
VendorName "eVGA"
BoardName "FX5500"
EndSection

Section "Screen"
Identifier "Screen0"
Device "Card0"
Monitor "Monitor0"
DefaultColorDepth 24
SubSection "Display"
Depth 24
Modes "720x480"
EndSubSection
SubSection "Display"
Depth 24
Modes "1440x480"
EndSubSection
SubSection "Display"
Depth 24
Modes "1920x1080"
EndSubSection
EndSection

Section "DRI"
Mode 0666
EndSection


The following is the Xorg.0.log file output as it pertains to TV Resolutions. Be sure to check this file to verify the output is compatable with your TV before selecting the TV's HDMI input. Be sure to look for supported resoutions of your TV.

Xorg.0.log File Output:

(II) Setting vga for screen 0.
(**) NVIDIA(0): Depth 24, (--) framebuffer bpp 32
(==) NVIDIA(0): RGB weight 888
(==) NVIDIA(0): Default visual is TrueColor
(==) NVIDIA(0): Using gamma correction (1.0, 1.0, 1.0)
(**) NVIDIA(0): Option "NoLogo" "1"
(**) NVIDIA(0): Option "SWcursor"
(**) NVIDIA(0): Option "ConnectedMonitor" "DFP"
(**) NVIDIA(0): Option "TVStandard" "HD1080i"
(**) NVIDIA(0): Option "RenderAccel" "True"
(**) NVIDIA(0): Option "MetaModes" "1920x1080"
(**) NVIDIA(0): Option "TVOverScan" "0.8"
(**) NVIDIA(0): Option "XvMCUsesTextures" "True"
(**) NVIDIA(0): Option "UseEdidDpi" "FALSE"
(**) NVIDIA(0): Option "DPI" "100 x 100"
(**) NVIDIA(0): Option "ModeValidation" "AllowNon60HzDFPModes, NoVertRefreshCheck, NoEdidMaxPClkCheck, NoHorizSyncCheck"
(**) NVIDIA(0): Enabling RENDER acceleration
(**) NVIDIA(0): TV Standard string: "HD1080i"
(**) NVIDIA(0): ConnectedMonitor string: "DFP"
(II) NVIDIA(0): NVIDIA GPU GeForce FX 5500 at PCI:1:0:0
(--) NVIDIA(0): VideoRAM: 262144 kBytes
(--) NVIDIA(0): VideoBIOS: 04.34.20.69.00
(II) NVIDIA(0): Detected AGP rate: 8X
(--) NVIDIA(0): Interlaced video modes are supported on this GPU
(--) NVIDIA(0): Connected display device(s) on GeForce FX 5500 at PCI:1:0:0:
(--) NVIDIA(0): Panasonic TH-42PD25U (DFP-0)
(--) NVIDIA(0): Panasonic TH-42PD25U (DFP-0): 135.0 MHz maximum pixel clock
(--) NVIDIA(0): Panasonic TH-42PD25U (DFP-0): Internal Single Link TMDS
(II) NVIDIA(0): Mode Validation Overrides for Panasonic TH-42PD25U (DFP-0):
(II) NVIDIA(0): AllowNon60HzDFPModes
(II) NVIDIA(0): NoEdidMaxPClkCheck
(II) NVIDIA(0): NoHorizSyncCheck
(II) NVIDIA(0): NoVertRefreshCheck
(WW) NVIDIA(0): Mode "1920x1080" is too large for Panasonic TH-42PD25U
(WW) NVIDIA(0): (DFP-0); discarding.
(WW) NVIDIA(0): Mode "800x600" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "800x600" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "800x600" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "800x600" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "800x600" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "1024x768" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "1024x768" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "1024x768" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "1024x768" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "1024x768" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "1152x864" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "1280x960" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "1280x1024" is too large for Panasonic TH-42PD25U
(WW) NVIDIA(0): (DFP-0); discarding.
(WW) NVIDIA(0): Mode "1280x1024" is too large for Panasonic TH-42PD25U
(WW) NVIDIA(0): (DFP-0); discarding.
(WW) NVIDIA(0): Mode "800x600" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "800x600" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "800x600" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "800x600" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "800x600" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "896x672" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "896x672" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "928x696" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "960x720" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "832x624" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "1280x768" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "1280x800" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "1152x768" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "1152x864" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "1400x1050" is too large for Panasonic TH-42PD25U
(WW) NVIDIA(0): (DFP-0); discarding.
(WW) NVIDIA(0): Mode "1440x900" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "1600x1024" is too large for Panasonic TH-42PD25U
(WW) NVIDIA(0): (DFP-0); discarding.
(WW) NVIDIA(0): Mode "960x600" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "960x600" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "1024x768" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "800x600" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "800x600" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "800x600" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "800x600" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "800x600" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "1024x768" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "1024x768" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "1024x768" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "1024x768" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "1152x864" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "1280x960" is too large for Panasonic TH-42PD25U (DFP-0);
(WW) NVIDIA(0): discarding.
(WW) NVIDIA(0): Mode "1280x1024" is too large for Panasonic TH-42PD25U
(WW) NVIDIA(0): (DFP-0); discarding.
(WW) NVIDIA(0): Mode "1280x1024" is too large for Panasonic TH-42PD25U
(WW) NVIDIA(0): (DFP-0); discarding.
(II) NVIDIA(0): Assigned Display Device: DFP-0
(II) NVIDIA(0): Validated modes:
(II) NVIDIA(0): "1920x1080"
(II) NVIDIA(0): Virtual screen size determined to be 1920 x 1080
(++) NVIDIA(0): DPI set to (100, 100); computed from -dpi X commandline option
(--) Depth 24 pixmap format is 32 bpp
(II) do I need RAC? No, I don't.
(II) resource ranges after preInit:
[0] 0 0 0xc0000000 - 0xcfffffff (0x10000000) MX[B]
[1] 0 0 0xe1000000 - 0xe1ffffff (0x1000000) MX[B]
[2] -1 0 0x00100000 - 0x3fffffff (0x3ff00000) MX[B]E(B)
[3] -1 0 0x000f0000 - 0x000fffff (0x10000) MX[B]
[4] -1 0 0x000c0000 - 0x000effff (0x30000) MX[B]
[5] -1 0 0x00000000 - 0x0009ffff (0xa0000) MX[B]
[6] -1 0 0xe0000000 - 0xe000ffff (0x10000) MX[B]
[7] -1 0 0xe0010000 - 0xe00107ff (0x800) MX[B]
[8] -1 0 0xe3000000 - 0xe3000fff (0x1000) MX[B]
[9] -1 0 0xe3005000 - 0xe3005fff (0x1000) MX[B]
[10] -1 0 0xe3004000 - 0xe30040ff (0x100) MX[B]
[11] -1 0 0xe3003000 - 0xe3003fff (0x1000) MX[B]
[12] -1 0 0xe3002000 - 0xe3002fff (0x1000) MX[B]
[13] -1 0 0xd0000000 - 0xcfffffff (0x0) MX[B]O
[14] -1 0 0xdc000000 - 0xdfffffff (0x4000000) MX[B](B)
[15] -1 0 0xd8000000 - 0xdbffffff (0x4000000) MX[B](B)
[16] -1 0 0xc0000000 - 0xcfffffff (0x10000000) MX[B](B)
[17] -1 0 0xe1000000 - 0xe1ffffff (0x1000000) MX[B](B)
[18] 0 0 0x000a0000 - 0x000affff (0x10000) MS[B](OprD)
[19] 0 0 0x000b0000 - 0x000b7fff (0x8000) MS[B](OprD)
[20] 0 0 0x000b8000 - 0x000bffff (0x8000) MS[B](OprD)
[21] -1 0 0x0000ffff - 0x0000ffff (0x1) IX[B]
[22] -1 0 0x00000000 - 0x000000ff (0x100) IX[B]
[23] -1 0 0x0000c100 - 0x0000c11f (0x20) IX[B]
[24] -1 0 0x0000c000 - 0x0000c07f (0x80) IX[B]
[25] -1 0 0x0000e200 - 0x0000e27f (0x80) IX[B]
[26] -1 0 0x0000e100 - 0x0000e10f (0x10) IX[B]
[27] -1 0 0x00000b70 - 0x00000b73 (0x4) IX[B]
[28] -1 0 0x00000970 - 0x00000977 (0x8) IX[B]
[29] -1 0 0x00000bf0 - 0x00000bf3 (0x4) IX[B]
[30] -1 0 0x000009f0 - 0x000009f7 (0x8) IX[B]
[31] -1 0 0x0000dc00 - 0x0000dc7f (0x80) IX[B]
[32] -1 0 0x0000db00 - 0x0000db0f (0x10) IX[B]
[33] -1 0 0x00000b60 - 0x00000b63 (0x4) IX[B]
[34] -1 0 0x00000960 - 0x00000967 (0x8) IX[B]
[35] -1 0 0x00000be0 - 0x00000be3 (0x4) IX[B]
[36] -1 0 0x000009e0 - 0x000009e7 (0x8) IX[B]
[37] -1 0 0x0000f000 - 0x0000f00f (0x10) IX[B]
[38] -1 0 0x0000d400 - 0x0000d47f (0x80) IX[B]
[39] -1 0 0x0000d300 - 0x0000d3ff (0x100) IX[B]
[40] -1 0 0x0000d200 - 0x0000d207 (0x8) IX[B]
[41] -1 0 0x00004c40 - 0x00004c7f (0x40) IX[B]
[42] -1 0 0x00004c00 - 0x00004c3f (0x40) IX[B]
[43] -1 0 0x0000e300 - 0x0000e31f (0x20) IX[B]
[44] 0 0 0x000003b0 - 0x000003bb (0xc) IS[B](OprU)
[45] 0 0 0x000003c0 - 0x000003df (0x20) IS[B](OprU)
(II) NVIDIA(0): Setting mode "1920x1080"
(II) Loading extension NV-GLX
(II) NVIDIA(0): NVIDIA 3D Acceleration Architecture Initialized
(II) NVIDIA(0): Using the NVIDIA 2D acceleration architecture
(**) NVIDIA(0): Option "BackingStore" "True"
(**) NVIDIA(0): Backing store enabled
(==) NVIDIA(0): Silken mouse enabled
(**) Option "dpms" "true"
(**) NVIDIA(0): DPMS enabled
(II) Loading extension NV-CONTROL
(==) RandR enabled
(II) Initializing built-in extension MIT-SHM
(II) Initializing built-in extension XInputExtension
(II) Initializing built-in extension XTEST
(II) Initializing built-in extension XKEYBOARD
(II) Initializing built-in extension XC-APPGROUP
(II) Initializing built-in extension SECURITY
(II) Initializing built-in extension XINERAMA
(II) Initializing built-in extension XFIXES
(II) Initializing built-in extension XFree86-Bigfont
(II) Initializing built-in extension RENDER
(II) Initializing built-in extension RANDR
(II) Initializing built-in extension COMPOSITE
(II) Initializing built-in extension DAMAGE
(II) Initializing built-in extension XEVIE
(II) Initializing extension GLX
(**) Option "CoreKeyboard"
(**) Keyboard0: Core Keyboard
(**) Option "Protocol" "standard"
(**) Keyboard0: Protocol: standard
(**) Option "AutoRepeat" "500 30"
(**) Option "XkbRules" "xorg"
(**) Keyboard0: XkbRules: "xorg"
(**) Option "XkbModel" "pc105"
(**) Keyboard0: XkbModel: "pc105"
(**) Option "XkbLayout" "us"
(**) Keyboard0: XkbLayout: "us"
(**) Option "CustomKeycodes" "off"
(**) Keyboard0: CustomKeycodes disabled
(**) Option "Protocol" "IMPS/2"
(**) USB Mouse: Device: "/dev/input/mice"
(**) USB Mouse: Protocol: "IMPS/2"
(**) Option "SendCoreEvents" "true"
(**) USB Mouse: always reports core events
(**) Option "CorePointer"
(**) USB Mouse: Core Pointer
(**) Option "Device" "/dev/input/mice"
(**) Option "Buttons" "5"
(==) USB Mouse: Emulate3Buttons, Emulate3Timeout: 50
(**) Option "ZAxisMapping" "4 5"
(**) USB Mouse: ZAxisMapping: buttons 4 and 5
(**) USB Mouse: Buttons: 9
(II) XINPUT: Adding extended input device "USB Mouse" (type: MOUSE)
(II) XINPUT: Adding extended input device "Keyboard0" (type: KEYBOARD)
(II) XINPUT: Adding extended input device "NVIDIA Event Handler" (type: Other)
xkb_keycodes { include "xfree86+aliases(qwerty)" };
xkb_types { include "complete" };
xkb_compatibility { include "complete" };
xkb_symbols { include "pc(pc105)+us" };
xkb_geometry { include "pc(pc105)" };
(II) USB Mouse: ps2EnableDataReporting: succeeded

In this mode the GUI seems to bleed beyond the screen. To correct this, I changed the GUI Size and Offset to the following in Setup > Appearance > 2nd screen:

X Size = 1780
Y Size = 1000
X Offset = 70
Y Offset = 40
Uncheck the box "Use GUI Size for TV Playback.

Also since the resolution is so high, you may want to select Font to "Big" instead of "Default" in Setup > Appearance > 1st Screen.

If you are also watching Analog TV through this HDMI input, like me, you may want to change the Aspect Overide setting to 16/9 instaed of auto in Setup > TV Settings > Playback> 1st Screen. This will fill the TV Screen with the program, instead of having black bars on each side of the program being played.

I hope it helps someone out. It took a lot of tweeking to get it configured. Enjoy!

_________________
--Brian
___________________
Backend / Frontend
Intel NUC mini PC kit NUC7i5BNH
Frontend
Intel NUC Mini PC Kit UDC3217BY
Frontend
Giada Mini PC
3 each WeChip Mini Air Mouse
2 - HDHomeRun Dual Tuners
OTA Amplified Antenna
Since 2003