GSB GC Crash to desktop

I just purchased the GC expansion from Red Marble, downloaded and installed it. Now I cannot start the game. Whenever I try to open it the game immediately crashes to the desktop.

I have an iMac with OS 10.6.7
Before I installed the expansion I had the latest version of GSB.

Has this happened to anyone else? What can I do to fix it?

There is an occasional issue with the campaign installer on certain Macs. If you’ll email us (support -at- redmarblegames - dot - com), we’ll fix you right up.