Hmm, doesn't happen here. I still think it's probably some kind of display or resource problem.
So, those strange icons on the desktop do not just disappear by themselves when you e.g. reboot the system? You have to manually remove them? When you say they're sound objects you've been using within Music Maker, what exactly would that look like? Can you provide a screen shot of your desktop in that state? That might be very interesting.