Hello, Today I got a 4 gb ram kit for my Macbook pro. I installed it and everything was working great and my macbook pro ran fine. Than I a few hours later I went to play C&C Tiberium Wars, and I got the message you need to turn off your computer with a black screen. Than I restarted and got a white screen, and it stayed that way until i restarted it a second time, and the whole process started over again. My macbook pro works with the 2 x 2gb sticks, and in the system profile it shows the 4 gb of ram, but it kept crashing when ever I got into something more intense. I've put the 2 x 1 gb sticks back in the C&C runs fine. My question is is the 2 x 2 gb sticks no good? The ram is transcend I got it off of CanadianRAM web site.