I have been using my PT 12 on Vista for about a year with no issues but lately when I hit play from the beginning of a song with audio in one track and midi in another, the scroll bar won't move, the midi doesn't play, but the audio level bars for the audio move as if its playing but no sound. After this happens the program won't shut down and I can't stop PT 12 even in the processes so I have to restart the computer and all works well for awhile