Video and audio becoming unmatched and herky jerky. Help!

[wiserd]

Hey, I'm trying to figure out what's wrong with my vid. I have to have all other applications closed for it to work right. And my computer is FAST. Or was when I got in a few years ago. +2Ghz. 1 gig MEMORY. And Hard Disk space for paging. I get a lot of complaints that my video and audio "don't match up." But they do! I timed it very carefully.

If anyone could help, I'd be appreciative.

width 640
height 480
audio
duration 3:51
bit rate 48kbps
audio format MPEG Layer-3

Video
Frame rate 29 frames/second
Data rate 198 kbps
Video sample size 24 bit
video compression DivX codec

File size 44.8 MB ( and a larger one around 65 MB with more footage)


Questions? Comments? Deep thoughts? All are welcome.
Thanks for your help!
[MOD: Just one thread is enough.]