Hi all, I'm trying to upgrade my 2011 Macbook Air from Lion 10.7.4 to the Mountain Lion GM by running the DMG file from my desktop. It runs through the installer just fine then reboots to complete the install, however it just reboots back into Lion 10.7.4 every time. I tried resetting the PRAM/NVRAM and repairing permissions - no luck. The same Mountain Lion GM file upgraded my MBP just fine. Any ideas? Thanks in advance!