Phil, I am on 10.2.6 and it usually pretty violent - the beachball spins and jitters and is no longer under mouse control. It does not respond to force quits and the only option is to hit the restart button. This even happens when openGL is turned off, so e-on obviously has some very low-level code that is messed up. I am hoping e-on tested the Mac a lot like guitta said - because right now trying to animate or even change materials in Vue4.1.2/mover is very frustrating. I will probably order it but I am sure hoping for some stability. Scott