Hi I've been running Avid MC 6.5 on a 2011 Macbook Pro with 4 gigs of RAM. It has run like a charm. I just upgraded to OSX 10.8.4 and upgraded the memory to 16 gigs and then upgraded to Avid MC 7. The video stutters quite a bit on playback now and the fans come on and the computer runs HOT while I'm editing. This never happened with MC 6.5 on the older operating system. I've had the entire computer tested by the people at Apple and everything checks out fine. I then completely re formatted my hard drive and re-loaded all software. I still have the same problem with MC 7 as before. Does anyone know how I can fix this?