1: I want to get Xine to use the mpeg2 decoder on my via board, so i would need to alter the startup line of xine, how ever, under the menu i cant move around or write anything in the field. Normaly it would highlight your selection but it dosent do so here, any ideas?

2: when i insert a cd or dvd, it dosent automatic unmount, so i would need to manualy unmount, tryed to search for a solution for this one, but dident find one ? only solution i found was to make a "unmount button" in mythtv.. isent there a way to get it to work as intended?

1) No idea why you can't modify a settings field. You can always try to find that field in the settings table and modify it through there (e.g. using phpmyadmin or the like).
2) Somewhere in the general settings is an option to monitor CD/DVD drives. That should take care of the mounting and unmounting for you.

For problem number one, are you using a keyboard or tring to edit it using a remote?

I am using a keyboard, dont have my remote working yet.

it is checked! so that´s not the problem.