I have a source mpeg PS which raises this error in utils.c. The timestamps look ok to me. The output with vanilla FFmpeg is pixellated and jittery. If I comment out the return -1 after the error msg the output is fine.

ffmpeg.exe -i test.mpg -y -target pal-dvd -vcodec copy -acodec copy -async 50 test_DVD.mpg
ffmpeg version 0.4.9-pre1, build 4747, Copyright (c) 2000-2004 Fabrice Bellard
  configuration:  --disable-debug --enable-a52 --enable-gpl --enable-memalign-hack
  built on Mar 17 2005 08:59:33, gcc: 3.2.3 (mingw special 20030504-1)
Input #0, mpeg, from 'C:\test.mpg':
  Duration: 00:00:12.1, start: 0.088856, bitrate: 5868 kb/s
  Stream #0.0: Video: mpeg2video, 720x576, 25.00 fps, 15000 kb/s
  Stream #0.1: Audio: ac3, 48000 Hz, stereo, 192 kb/s
Output #0, dvd, to 'C:\test_DVD.mpg':
  Stream #0.0: Video: mpeg2video, 720x576, 25.00 fps, q=2-31, 15000 kb/s
  Stream #0.1: Audio: ac3, 48000 Hz, stereo, 192 kb/s
Stream mapping:
  Stream #0.0 -> #0.0
  Stream #0.1 -> #0.1
error, non monotone timestamps 32400 >= 0
error, non monotone timestamps 75600 >= 0
error, non monotone timestamps 118800 >= 0
error, non monotone timestamps 162000 >= 0
error, non monotone timestamps 205200 >= 0
error, non monotone timestamps 248400 >= 0
error, non monotone timestamps 291600 >= 0
error, non monotone timestamps 334800 >= 0
error, non monotone timestamps 378000 >= 0
error, non monotone timestamps 421200 >= 0
error, non monotone timestamps 464400 >= 0
error, non monotone timestamps 507600 >= 0
error, non monotone timestamps 550800 >= 0
error, non monotone timestamps 594000 >= 0
error, non monotone timestamps 637200 >= 0
error, non monotone timestamps 680400 >= 0
error, non monotone timestamps 723600 >= 0
error, non monotone timestamps 766800 >= 0
error, non monotone timestamps 810000 >= 0
error, non monotone timestamps 853200 >= 0
error, non monotone timestamps 896400 >= 0
error, non monotone timestamps 939600 >= 0
error, non monotone timestamps 982800 >= 0
error, non monotone timestamps 1026000 >= 0
error, non monotone timestamps 1069200 >= 0
frame=  308 q=75983.7 Lsize=    7838kB time=12.3 bitrate=5239.0kbits/s
video:8268kB audio:287kB global headers:0kB muxing overhead -8.385885%


with line 2154 in utils.c commented out i get:


frame=  308 q=75983.7 Lsize=    8732kB time=12.3 bitrate=5836.5kbits/s
video:8268kB audio:287kB global headers:0kB muxing overhead 2.063595%