So,here`s my question, I would be glad if you could help me out!

I installed GI Jazz 3 with my perfectly stable running Sibelius and everytime I switch the player from General MIDI to the ARIA player and confirm the change, Sibelius crashes down (Max OS X 10.6.7.)

It won`t even let me play the music,
it just quits after the change of settings.

Did anybody have this problem already and knows what the reason for this could be?

All the best