I did some more work on the issue above. There are functions with in the MusicManager that call the UserManager to get a user's ID. When I comment out these calls then the access errors go away. Well the user manager has some calls back to mxml that tell the class that changes where made. My best guess is this is where it stems into the code that is randomly throwing errors. But, it compiles fine and runs fine on a device. Is there something with test cases which doesn't invoke the UI?