Video and Audio Strangely Out of Sync

[Shoal]

I wasn't sure which forum would be best for this, so I apologize if this doesn't work...
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Okay, here's the issue:

I have ten video files and ten audio files. One audio file for each video file. I personally checked each video file and its corresponding audio file to make sure they were exactly the same length, down to the third decimal point. But when I join them all together in the proper order, here are my lengths:

Video: 0:21:22.700
Audio: 0:21:22.697

The video files are all compressed with exactly the same codec and settings at exactly the same constant framerate. The audio files are all 48kHz stereo WAVs.

ARGH.

This problem started, I think, when I created my own WAV and video to join the other nine. The first nine were captured from a video game using FRAPS, while the tenth was a video made to search as a "break" between each of the captured videos. But I made sure everything was exactly the same between my video and the other ones. I don't know what happened! I even captured my own video on FRAPS and then compressed it just like the other ones!

Might it have something to do with the fact that one muxed video has an audio interleave duration of 61ms, three others have 37ms, and the rest at 33ms? How would I even change that?

Any help would be greatly appreciated.

Note, I'm using VirtualDub and Audacity.

[newpball]

Oops, wrong topic.

[manono]

The audio is three thousandths of a second less than the video? If you have synch problems it's not because of that.

[Shoal]

Just because I can't perceive the out-of-sync doesn't mean it isn't there. I've done this same sort of project three times before, and every time the video and audio were exactly the same length. But now... now that's not the case. I have no idea why. It doesn't make sense.

[Shoal]

Well, I managed to fix the problem. I had originally capped my own video (I made a video and then captured it) with FRAPS for the break, but I had done it with no sound and later added a custom-made WAV. This time I added the custom-made WAV to the video before capping it, so FRAPS could form its own WAV off my own. This new WAV somehow solves the problem - the video and audio come out exactly the same length!