Ran the Tune network thing, came through full bars all the way to the top of HD.
When i do watch things downstairs through the xbox, i shut everything down on the PC and just let it sit, or do a fresh reboot and leave it alone after booting.
on average when i dont have anything running i will have about 1.5gb of memory available, and 0 processor use (other than the little tiny bits here and there for whatever windows wants it for).
I even went and cleaned space on my Xbox hard drive to see if that would help as i was down to about 1gb left.
Odd thing too, is it hasnt been happening with all videos, maybe about 75%. the 25% it is not skipping on seems random, some high quality, some low. some big files, some small, etc. Maybe i just need to get a new router and cables, the ones i have are getting kinda old....