I just tried to convert an MPEG I downloaded (Chappelle's Show) to avi using FlaskMPEG but it doesn't seem to be working

I'm having the same problem even when using another version of flaskMPEG. What happens is that it only records the first frame then stops but continues to process the audio. I've tried converting other MPEGs and they seem to work fine with some minor problems.

I'm using divx 5.02 and Fraunhoffer IIS MP3. Anyone know what the problem could be? Thanks