Could not open /dev/sequencer - Probably there is another program using it.

This is a message I get when I try to playback a midi file with Kmid. As far as I can tell there is no other program using it, unless it would be KDE itself. Does it?

What could be the other causes of this? Going to the Yast Multimedia I see that the sequencer is supposed to have started. All other audio seems OK and working.