I am pulling my hair out trying to figure out a problem. I just installed a Quadro FX 4800 in my Mac Pro and installed the latest drivers. Everything including PPro CC 2014 works. But Quicktime Pro brings the system to a standstill, the mouse cursor freezes and jumps every 5-10 secs like the system is in slow motion. If I quit Quicktime Pro 7.6.6 everything goes back to normal. It's only Quicktime Pro that causes this. I need QT Pro to work. QT 10.2 works for playback normally. If I boot into safe mode QT Pro works! So maybe it's Quartz Extreme causing this? Can't think of what else to try. Thought maybe someone else has heard of this. I am running a Blackmagic board and eSATA board in the Mac.