Yeah, I recently lowered the res of all the videos in question, Changed my hardware to a 4 ghz 8 core amd with 20 gigs of DDr 3, and a GTX 750 (was a 550 ti). The problem still persists for me. It wouldnt be so bad but I included some FMV style games and the preview of the game its self has the audio go out of sync while the characters are speaking in the video, which to be honest drives me a little crazy.
Now the audio is perfectly in sync when the game is actually being played. Its simply the videos I have for my snaps.