I am having a problem with instruments that stop playing. I have a large, rather complex orchestration (which may be the cause of the problem—too many instruments?). As I work on it, I discover that some instruments have stopped playing. Closing the file, restarting the computer, and reopening the file doesn't correct it. And switching that staff to another Garritan instrument doesn't work either. The only thing that I have found that works is to create a new staff and delete the old one. It fixes the problem, but it's maddening to have to do that continually. I spend a lot of my time fixing the file. Also, when I add a new staff, it messes up all my staff sets and I have to create them all from scratch (which is another thing that bugs me—I wish there were a way to create a new staff in an existing file without it being added to all the staff sets.) 

Anyway, have any of you good folks experienced this problem of instruments ceasing to work?