Hi, there.
I've successfully used your tool to encode a variety of videos to a format playable on my iriver E100. However, I have noticed that the MP4 videos available at DemocracyNow?.org fail to convert. Even if I leave them for hours, the bar does not even start to move across, so eventually give up, fearing that it will never actually stop. Since the whole computer slows down, leaving it going for a couple of days is out of the question. (In fact, it doesn't even seem to give all the memory back when it finishes.)
Meanwhile, it is really creating a new file (even though the bar isn't moving), which ends up being much bigger than the original file. It has to be deleted.
I've tried downloading the same videos in RealMedia? format instead, and iriverter is able to successfully encode them within a reasonable period of time, with the progress bar working.