I'm having 2 minor problems/bugs with passthrough (video):
1) Passthrough won't accept frame sizes that aren't divisable by 16 (in the original file, ffmpegx gives the error)
2) When I run a passthrough video and recompress aduio (to mp3), ffmpegx automatically puts a .mp3 extension on the end file even though it is an .avi file!

Can I get around one? Is two a known issue or am I doing something wrong?