Unable to find a suitable output format for 'ffmpeg2theora'

I've set up the Video module and have it successfully converting to mp4 and flv, but am unable to convert to ogg/theora.

Following advice in some other issues here I had to make a couple of changes to get ffmeg2theora at least attempting the conversion; in my transcoder settings I've selected 'Use -vf "pad:w:h:x:y:c" for padding' and I've modified my html5_ogv.inc file to use '!cmd_path ffmpeg2theora -o !convertfile !videofile'

This is the error message recorded in my log.

Video conversion failed for preset html5_ogv. FFMPEG reported the following output: FFmpeg version 0.6.2, Copyright (c) 2000-2010 the FFmpeg developers built on Jun 11 2011 09:36:40 with gcc 4.2.1 (Apple Inc. build 5666) (dot 3) configuration: --disable-debug --prefix=/usr/local/Cellar/ffmpeg/0.6.2 --enable-shared --enable-pthreads --enable-nonfree --enable-gpl --disable-indev=jack --enable-libx264 --enable-libfaac --enable-libmp3lame --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libxvid --enable-libfaad libavutil 50.15. 1 / 50.15. 1 libavcodec 52.72. 2 / 52.72. 2 libavformat 52.64. 2 / 52.64. 2 libavdevice 52. 2. 0 / 52. 2. 0 libswscale 0.11. 0 / 0.11. 0 Unable to find a suitable output format for 'ffmpeg2theora'

A lot of searching here and elsewhere has so far left me non the wiser!