VisualHub: Incomplete conversions

I've been using VisualHub v. 1.23 to convert .avi into .MP4 to watch on my PSP. It's always done the conversions without any problems. However a few avi files that I recently converted came up short. Rather then getting the full 40 minutes of the avi file I only get 30 min on the MP4, missing the last 10 minutes of the video. I tried converting again on the files this occurred on, only to have VisualHub not convert the avi files completely again.

Anyone else have/had a problem like this?

Could it just be the avi files are corrupt? They play fine on my MacBook...

Any help or advice would be appreciated.

Or even a recommendation for a better application for converting my avi files to PSP MP4s would be nice. I liked VisualHub because it was quick and also made the strange title and thumbnail for PSP.