I just got my MBP and upgraded the ram to 4gb of crucial ddr3, along with a 500gb WD scorpion. The problem is when I try to watch a full screen episode of a tv show that I have saved on my computer, the video will stutter, the picture will freeze but the sound will go on. Sometimes the picture starts moving again, but sometimes I need to pause or go back by "scrubbing". Now, I do have a few programs running in the background, usually firefox, ichat, transmission and sometimes iTunes. But they aren't really actively being used except for transmission as it's downloading a file. I tried to open up my activity monitor but nothing seems wrong, as I had over a gig of ram left and cpu wasnt even close to being maxed out. I did try to run it again after just restarting my computer and then it ran fine, but I feel like it should be able to run a few programs without lag, as my old single core 1.76ghz pc had no problem doing this. Maybe this is too much to ask?