As o-dog says, the cause of the Access Violation issue experienced by users of recently introduced Mac models has now been identified. By default, these machines start up with Mac OS 10.6's 64-bit kernel as opposed to the 32-bit kernel used in the past.
We are looking at ways to resolve this issue, but in the meantime it can be worked around by starting up with the 32-bit kernel. For information on this visit:
http://support.apple.com/kb/ht3773
Thanks for providing information to help us to identify this issue - please let us know if it resolves the problem that you are having.