"laggy" sound + smooth playback on MPEG, help plez

[eliteplayer]

I converted a WMV to MPEG with TMPGEnc
so after 30minutes, I played it, it has smooth playback @ 25 fps/sec but the sound is slow by 1.5 to 2 seconds, how do I fix that without converting again?

is this the software problem? because I tried RealOne, Media Player 6.4, Media Player 8... all does the same thing

I got no problem with some of the MPEG converted from AVI

AMD 2700+, 256 ddram, radeon9600, dr divx, several codec packs, media player 6.4, media player 8, realone player.

[eliteplayer]

man what's wrong with the movie

i converted the MPG to AVI using FlaskMPEG
now I have flaskOut.avi / flaskAudioOut.mp2

so i converted the flaskAudioOut.mp2 using winamp to turn it into a wav file

then i join them with virtualdub, still laggy sound

[eliteplayer]

please help