The polysix in -mono -hnp mode seems to mess up it's monophonic code assignment when sequencing from rosegarden (I haven't experienced it while playing live).
Occasionally (and I don't know how to cause this bug), the polysix will appear to be totally silent, even when reciving note on events, from both sequencer and keyboard.
Holding one key and then pressing one higher than it ('cos i'm using the -hnp option), causes the polysix to play notes AND drop back to the first key played, as if the note had originally sounded, which it didn't.. Releasing the key results in a note off, but pressing either the same key or another key, no sound comes out of the polysix...
PS. I'm using Rosegarden as my midi sequencer