I just finished installing Jabb and tried openning two instruments (one for the rhythm section and a seperate one for brass). I hit play and 2 bars in a horrible digital cacophony assaulted my ears. When I removed the second JABB player the rhythm tracks play fine. Also the graphics on the second JABB player didn't work. The menu showed but I couldn't select any instruments. I had to close the first JABB player and reselect the second JABB player and then I could choose the instruments. Trying to play both created the noise.