Hi, I have an update on this. Today I had the chance to get my hands on a 2009 MacBook Pro of a friend that still runs 10.6.8. And guess what: The CRJ 64bit worked. Let me put this straight: Apple very clearly says that what I'm doing is NOT compatible with OSX 10.6. Nevertheless, it appears to work. But: As this is strictly not supported by Apple, it may break any time in the future. That is it might break any time X-Plane is updated, the CRJ is updated or my XCode is updated and thus the next CRJ update depends on a newer XCode. As of now, CRJ 1.5.3/64bit works on 10.6.8, but I don't guarantee any support in the future for this configuration. If it works for you, fine. If it doesn't, you were warned. Philipp