[humdrumprune]

Hmm....Interesting the only difference in our systems is you have Lion 10.7.1 and I have 10.7.0. But i'm almost sure that wouldn't matter.

I have tried everything under the sun to get it to work, I will attempt to reinstall Pro Tools again, what Audio Drivers do you use for playback? i.e. 003, 002?

Thanks for letting me know yours is working that means there might be some hope.
I just received an email from Sibelius Support saying that it is a Pro Tools Issue and that I need to contact Pro Tools Support, even though it is Sibelius that is not opening.