ok, I've been working on this one for 8 hours, maybe it's time to give my more experienced friends a turn. You'll probably solve it in a few minutes.

I installed Rosegarden, a MIDI composition program. MIDI works consistently when played through Timidity, of course, as it is simply converted to .wav and then played. The strange behavior is that Rosegarden only plays MIDI every once in a while, usually right after a reboot. It has so far only worked in the first time the program is loaded in a given boot.

Very confusing... must be something simple if it works sometimes, right?