Re-Post, my first message has vanished!
I created a matroska file simply with mkvmerge -o test.mkv -A
(-A excludes the audio from the vob file)
Mplayer can play the resulting test.mkv perfectly
Xine, however, simply scans through the entire contents of the
file (noticeable by the disk activity), but never plays any
video. Do I need to do anything special to get this working?