please try a build from http://firefogg.org/nightly/ or the latest release from http://v2v.cc/~j/ffmpeg2theora/ the version in ubuntu is outdated and might have the problems you desribe.
please try a build from http:// firefogg. org/nightly/ or the latest release from http:// v2v.cc/ ~j/ffmpeg2theor a/
the version in ubuntu is outdated and might have the problems you desribe.