[MEncoder-users] Destroyed audio stream

[double]

Hi,

If I transcode a flash video with the following command line, the audio 
stream
is destroyed (mencoder RC1, LAME package from Ubuntu 7.04)

mencoder source.flv -of lavf -lavfopts 
i_certify_that_my_video_stream_does_not_use_b_frames
-ovc copy -oac mp3lame -lameopts cbr:br=64 -channels 1 -srate 22050 -o 
output.flv

Source-file:
http://www.doppelbauer.name/source.flv

What is the mistake?

Thank you very much
Markus Doppelbauer