Not sure what happened. Everything's been working great, but suddenly there are no thumbs being created when I upload .mov movies. Flash movies work fine, and I haven't tried other formats in the past couple days. Is this a mencoder problem? I'm not sure how the thumbs are generated exactly.
I looked in the debug.txt file, and everything seems to be working fine.
Here's a snippet from the debug.txt for the last .mov movie I uploaded:

2007-12-14 11:00:11 Video id: 160
2007-12-14 11:00:11 Calling ffmpeg-php -> ffmpeg_movie()
2007-12-14 11:00:11 Get video duration - START
2007-12-14 11:00:11 Get video duration - END
2007-12-14 11:00:11 DURATION: 144.853333
2007-12-14 11:00:11 Create Thumbnail - START
2007-12-14 11:00:27 Create Thumbnail - END
2007-12-14 11:00:27 CONVERT COMMAND:

It seems like the thumbnail command is being executed, but the thumbnail never ends up in my thumbs folder.

Any ideas?