Archos Jukebox Multimedia

I bought a archos Jukebox Multimedia. 
Its a mp3 player with a hard disc, which can also play 
divX Mpeg4 Video simple Profile Mpeg Files.(according documentation)
I tried to use ffmpeg/transcode to produce streams which my device accepts,
but always complaining: "stream not playable", but no error indication"

Has anybody successfully used transcode/ffmpeg to create a video file valid 
for Archos Jukebox Multimedia and could tell me the
"VERY TRICKY" options to use for it to work ?


rds Guenther