I get the following error "Segmentation fault" when I try to convert ogg files to mp3.

$ ffmpeg -i uploads/audios/vocal2.ogg -vn -ab 64k -ac 1 -ar 22050 -acodec 
libmp3lame uploads/audios/vocal2.mp3
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
FFmpeg version SVN-r10851, Copyright (c) 2000-2007 Fabrice Bellard, et al.
 configuration: --enable-libmp3lame --enable-libogg --enable-libvorbis 
--disable-mmx --enable-shared --enable-libfaadbin --enable-libfaad 
--enable-libfaac --enable-liba52bin --enable-pp --enable-pthreads 
--enable-gpl --disable-strip --enable-libvorbis --enable-libxvid
 libavutil version: 49.5.0
 libavcodec version: 51.47.0
 libavformat version: 51.17.0
 built on Oct 25 2007 11:08:08, gcc: 3.2.2 20030222 (Red Hat Linux 3.2.2-5)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Input #0, ogg, from 'uploads/audios/vocal2.ogg':
 Duration: 00:00:20.1, start: 0.854785, bitrate: 102 kb/s
 Stream #0.0: Audio: vorbis, 44100 Hz, stereo, 112 kb/s
Output #0, mp3, to 'uploads/audios/vocal2.mp3':
 Stream #0.0: Audio: libmp3lame, 22050 Hz, mono, 64 kb/s
Stream mapping:
 Stream #0.0 -> #0.0
Press [q] to stop encoding
Segmentation fault