no audio after a few secs

[rohan12]

i just downloaded a movie. i tried to play the movie using crystal player. the movie plays fine except that just abt 3 secs after the movie begins the sound stops. i tried playing the movie in DivX Playa and it didn't play at all. I played it in windows media player and the movie plays and there is sound but the video qulity is much worse than when i play it in crystal. I tried to extract the audio using TMPGEnc but the same thing...audio for 3-4 secs then nothing. What is the problem? The file properties according to nandub are:
Video compression DivX MPEG-4 fast motion
Audio:
44100 hz stereo
sample precision 0 bit (????)
Fraunhoffer IIS mpeg layer 3 codec
preload skew 0 secs

please help