I have some quicktime files (.mov) files that I need to convert to .mpeg format.

When I downloaded the .mov files, the files got to 98% and stopped. This results in the movies playing to a certain point and then the video halts, but the audio keeps playing. I can fast forward past the bad spot, and the video will continue to play. I was wondering if there was a program that repairs mov files? Something like the equivalent to asftools?
When I try to convert the files in TMPGenc, it fails every time.
I appreciate any help,
T