I've been reading many threads on the matter here already and I'm seeing many people successfully inserting their 1600mhz 8GBs of RAM into their 2009 unibody MBP that is suppose to only run 1066mhz RAM, but of course the computer is allowed for this to work.. However I'm holding here 8GBs of Kingston RAM, 1600mhz and would love for it to work on my MBP. However upon inserting these sticks I'm greeted with only a black screen and three odd beeps. Upon my putting in the original 1600mhz 4GBs of RAM that came stock with the MBP, the issue goes away. I've also done this one stock at a time and as you would expect, the stock works on a single basis but the Kingston does now. I'm seriously stumped only because so many of the community seems to have varying results.