I just got a new G5 (dual 2.5, GeForce 6800 video card) and it seems to me that some video files (Real, AVI, WMV but not DVD or mpeg so far) get out of sync with the audio). Not all files are affected.
It could just be a coincidence that since upgrading to the G5, I just happened to have encountered a higher number of misencoded or not-quite-Mac-compatible files, though.
So I thought I'd through the question out there . . . anybody else notice this?