I'm using a 15" 2.33 GHz Intel Core Duo Macbook Pro, with 3GB 667 Mhz DDR2 SDRAM, with Snow Leopard. Western Digital 320GB 7200 drive. I've recently been having video playback issues, starting within Final Cut Pro. The clip will play fine at first but then stutter and freeze on and off. I have to constantly stop and play to get through it. And now I'm having similar issues while playing HD clips with Quicktime. Any ideas?