root@stuv-workstation:/home/stuv/Desktop/temp music/Götz Widmann# ffmpeg -i Joint\ Venture.mp3 Joint\ Venture.ogg -vn
ffmpeg version 0.8.7.git-7d531e8, Copyright (c) 2000-2011 the FFmpeg developers
  built on Dec 12 2011 19:11:42 with gcc 4.4.5
  configuration:
  libavutil    51. 32. 0 / 51. 32. 0
  libavcodec   53. 43. 0 / 53. 43. 0
  libavformat  53. 24. 0 / 53. 24. 0
  libavdevice  53.  4. 0 / 53.  4. 0
  libavfilter   2. 53. 0 /  2. 53. 0
  libswscale    2.  1. 0 /  2.  1. 0

Seems stream 1 codec frame rate differs from container frame rate: 50000.00 (50000/1) -> 25.00 (25/1)
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Joint Venture.mp3':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: isomavc1mp42
    creation_time   : 2008-09-05 13:50:12
  Duration: 00:01:40.64, start: 0.000000, bitrate: 630 kb/s
    Stream #0:0(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, s16, 124 kb/s
    Metadata:
      creation_time   : 2008-09-05 13:50:12
      handler_name    : (C) 2007 Google Inc. v06.24.2007.
    Stream #0:1(und): Video: h264 (Baseline) (avc1 / 0x31637661), yuv420p, 480x360 [SAR 1:1 DAR 4:3], 500 kb/s, 25 fps, 25 tbr, 25k tbn, 50k tbc
    Metadata:
      creation_time   : 2008-09-05 13:50:12
      handler_name    :
[buffer @ 0x1bcc900] w:480 h:360 pixfmt:yuv420p tb:1/1000000 sar:1/1 sws_param:
Output #0, ogg, to 'Joint Venture.ogg':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: isomavc1mp42
    creation_time   : 2008-09-05 13:50:12
    Stream #0:0(und): Video: none, yuv420p, 480x360 [SAR 1:1 DAR 4:3], q=2-31, 128 kb/s, 90k tbn, 25 tbc
    Metadata:
      creation_time   : 2008-09-05 13:50:12
      handler_name    :
    Stream #0:1(und): Audio: none, 44100 Hz, stereo, s16, 128 kb/s
    Metadata:
      creation_time   : 2008-09-05 13:50:12
      handler_name    : (C) 2007 Google Inc. v06.24.2007.
Stream mapping:
  Stream #0:1 -> #0:0 (h264 -> ?)
  Stream #0:0 -> #0:1 (aac -> flac)
Encoder (codec none) not found for output stream #0:0