Hi Josh, did you ever find a solution to your crashing Mac Pro? I have a similar issue where a project will crash on one machine, but works fine on an older Mac Pro. Both versions of FCP are the same point release of FCP7, and the OS on both are the same. I can;t for the life of me work out where the issue lies. I have run TechTool Pro, no issues, Disk Warrior run to sort out permissions, directories, etc.