I have noticed my syslog is spamming "kernel: eth0: freeing mc frame" 30+ times per second. There are no obvious problems caused by this issue, but the system feels a bit less responsive than before.
From what I can glean from searching, this may be related to the net driver (Ethernet Pro 100 card) and IPV6. I will try to troubleshoot the issue and post any of my findings. If you are seeing the same issue or have already solved it, please let me know.