Hi, I have a 15inch MBP 2.8Ghz 5,3 (unibody with SD slot, up-to 8GB ram). I've purchased a single 4GB module from Crucial but cannot get the machine to act stable when running with the 9400M onboard graphics selected (as opposed to the faster, dedicated 9600). This is based on removing a factory supplied 2GB and replacing with the 4GB to give a total of 6GB. The screen exhibits random quick flashes of corruption in small areas and then eventually the system experiences a kernel panic after 5-10 minutes. There seems something about this 4GB module and the 9400M, I'm guessing as it shares the system RAM as opposed to having its own. Has anyone else had a similar experience? I was thinking of getting another 4GB module to have a matched pair of 8GB but it would be an expensive experiment if it doesn't solve it. Thanks in advance, Andrew.