Here's the description of the problem:
Video and audio are IN sync in fraps raw footage (everything's fine).
Encoding in Virtualdub a/v is in sync. (all good so far)
Encoding in anything else video and audio are out of sync after encoding. Audio plays about 1-2.5 secs before video starts. (bad playback locally using Media Player Classic Home Cinema).
Problem is the setting "Zero Latency" from the x264vfw codec settings. That needs to be checked to fix the problem. (Unchecked the problem occurs during local playback on media player classic).
To note: even if the local playback is out of sync, when uploaded to youtube the video and audio will be back in sync from youtube's processing.
Remember to CHECK Zero Latency option in x264vfw codec settings to avoid this out of sync issue when encoding using Sony Vegas or any other compressor besides VirtualDub (which didn't have this problem).
It took a long time for me to find that fix because most of the stuff about out of sync audio out there is about a slow drift off problem (which I didn't have) instead of this immediate a/v sync problem. So maybe this will help if you're recording with fraps and encoding with x264vfw.
