I belong to a couple of 3D Animations forums that use a program called Carrara from DAZ3d.com! The latest version DOES not play well with LION and certainly not MOUNTAIN LION! AS with my self a few are or already have bought new MACPROs as I wish to in 2 weeks.. Some say simply DOWNGRADE the OS From Lion and or mountain lion with Leopard which is what I have read on here you can do, but many say in these forums that it is nearly impossible to DOWNGRADE from lion. They said you have to do a lot of painstaking BS to downgrade everything correctly and if you don't know what you are doing your headed for trouble. In my case IF I CAN! I plan to take my new macpro out of the box and go right ahead and try to INSTALL LEOPARD before I install any software! PLEASE ADVISE!