OK, so this has been a problem with MC15 and now 16.
The program opens OK, I can get music playing, or my TV tuner working then the prog is away with the faeries! The display goes into very long hangs, with the cursor showing a turning circle. These hangs can be as long as 30 seconds, music is still playing or TV working, but the program is completely unresponsive until it comes back from it's trip to the faeries. I don't have this problem with any other software, and I don't have IE9 installed!