How do you splice out a part of an xvid encoded avi file, with ffmpeg? (no problems with other files)

Im using the following command, which works for most files, except what seems to be xvid encoded ones

/usr/bin/ffmpeg -sameq -i file.avi -ss 00:01:00 -t 00:00:30 -ac 2 -r 25 -copyts output.avi

So this should basically splice out 30 seconds of video + audio, starting from 1 minute mark.

It does START encoding at the 00:01:00 mark but it goes all the way to the end of the file for some reason, ignoring that I want just 30 seconds.

The output looks like this.

FFmpeg version git-ecc4bdd, Copyright (c) 2000-2010 the FFmpeg developers
  built on May 31 2010 04:52:24 with gcc 4.4.3 20100127 (Red Hat 4.4.3-4)
  configuration: --enable-libx264 --enable-libxvid --enable-libmp3lame --enable-libopenjpeg --enable-libfaac --enable-libvorbis --enable-gpl --enable-nonfree --enable-libxvid --enable-pthreads --enable-libfaad --extra-cflags=-fPIC --enable-postproc --enable-libtheora --enable-libvorbis --enable-shared
  libavutil     50.15. 2 / 50.15. 2
  libavcodec    52.67. 0 / 52.67. 0
  libavformat   52.62. 0 / 52.62. 0
  libavdevice   52. 2. 0 / 52. 2. 0
  libavfilter    1.20. 0 /  1.20. 0
  libswscale     0.10. 0 /  0.10. 0
  libpostproc   51. 2. 0 / 51. 2. 0
[mpeg4 @ 0x17cf770]Invalid and inefficient vfw-avi packed B frames detected
Input #0, avi, from 'file.avi':
  Metadata:
    ISFT            : VirtualDubMod 1.5.10.2 (build 2540/release)
  Duration: 00:02:00.00, start: 0.000000, bitrate: 1587 kb/s
    Stream #0.0: Video: mpeg4, yuv420p, 672x368 [PAR 1:1 DAR 42:23], 25 tbr, 25 tbn, 25 tbc
    Stream #0.1: Audio: ac3, 48000 Hz, 5.1, s16, 448 kb/s
File 'lol6.avi' already exists. Overwrite ? [y/N] y
Output #0, avi, to 'lol6.avi':
  Metadata:
    ISFT            : Lavf52.62.0
    Stream #0.0: Video: mpeg4, yuv420p, 672x368 [PAR 1:1 DAR 42:23], q=2-31, 200 kb/s, 25 tbn, 25 tbc
    Stream #0.1: Audio: mp2, 48000 Hz, 2 channels, s16, 64 kb/s
Stream mapping:
  Stream #0.0 -> #0.0
  Stream #0.1 -> #0.1
Press [q] to stop encoding
[mpeg4 @ 0x17cf770]Invalid and inefficient vfw-avi packed B frames detected
[buffer @ 0x184b610]Buffering several frames is not supported. Please consume all available frames before adding a new one.
frame= 1501 fps=104 q=0.0 Lsize=   15612kB time=30.02 bitrate=4259.7kbits/s    ts/s
video:15303kB audio:235kB global headers:0kB muxing overhead 0.482620%

if I convert this file to mp4 for example, and then perform the same action, it works perfectly.