[joehill@node1:southpark>$]ffmpeg -i south.park.1110.dsr.xvid-xor.avi southpark_1110.mp4
FFmpeg version SVN-r10107, Copyright (c) 2000-2007 Fabrice Bellard, et al.
  configuration: --prefix=/usr --enable-gpl --enable-pp --enable-pthreads --enable-liba52 --disable-debug --enable-shared --enable-libxvid --enable-libfaad --enable-libfaac --enable-libmp3lame
  libavutil version: 49.5.0
  libavcodec version: 51.41.0
  libavformat version: 51.12.2
  built on Aug 14 2007 12:03:08, gcc: 4.1.1 20060724 (prerelease) (4.1.1-3mdk)

Seems stream 0 codec frame rate differs from container frame rate: 23.98 (65535/2733) -> 23.98 (23976024/1000000)
Input #0, avi, from 'south.park.1110.dsr.xvid-xor.avi':
  Duration: 00:21:41.7, start: 0.000000, bitrate: 1127 kb/s
  Stream #0.0: Video: mpeg4, yuv420p, 512x384, 23.98 fps(r)
  Stream #0.1: Audio: mp3, 48000 Hz, stereo, 128 kb/s
File 'southpark_1110.mp4' already exists. Overwrite ? [y/N] y
Output #0, mp4, to 'southpark_1110.mp4':
  Stream #0.0: Video: mpeg4, yuv420p, 512x384, q=2-31, 200 kb/s, 23.98 fps(c)
  Stream #0.1: Audio: libfaac, 48000 Hz, stereo, 64 kb/s
Stream mapping:
  Stream #0.0 -> #0.0
  Stream #0.1 -> #0.1
[mpeg4 @ 0xb7e26568]removing common factors from framerate
[mpeg4 @ 0xb7e26568]timebase not supported by mpeg 4 standard
Error while opening codec for output stream #0.0 - maybe incorrect parameters such as bit_rate, rate, width or height