I have a very strange problem. My system (iMac/10.6.8) was playing back my score just fine. Now, it either doesn't play at all or I get a speaker-blowing SQUONK noise when i start the piece. I have tried everything imaginable, including re-installing a fresh copy of Musescore, to no avail. I moved a copy of my piece over to my old Mac, and it plays fine! I'm using the TimGM6 soundfont that came with the program, and it is set up properly in the synthesizer section. Regular iTunes music and everything else plays normally on this computer. Has anyone else had this happen or knows what happened?