In ProTools, when hitting the spacebar to stop playback while mixing or editing, the Cremona Quartet instruments don't stop if they're in mid-note at the stop point. To get them to quit, you have to find a spot in the file with a Note Off - send in the midi to stop the loop. Even Pro Tools' "All Notes Off" command doesn't stop them from continuing to loop. So far, the only solution is to either resume playback or find a spot in the file with a "Note Off" message in the midi and hit play there. It's annoying, really slows down the mix/edit process. Any known workarounds?