Hi, I ordered this 2x2gb ram from ebay. I thought it should have been the correct one with all the right info. Today the RAM arrived (at last) and I have a doubt that it isn't with correct speed. There is a sticker which says: 2GB PC2-5300 DDR2-667MHZ CL5 240-PIN DIMM. Notice the PIN-count. So the problem is either the speed is not 667mhz (could be 800mhz...) or the pin count is wrong. I have read that it should be 200-pin, but actually the new RAM is looking just the same as my current RAM (which works fine) and it works with the older one. Now my Macbook shows 3GB of installed RAM. MacBook reboots only with one older + one new RAM in it, not when the both 2GB RAMs are in. What I have is only black screen right after the reboot with the two 2gb rams installed. I read two threads from this forum: MacBook won't boot with new RAM. and MacBook Won't Boot while Upgrading RAM They had a conclusion that the RAM was clocked higher than it should have. What could be wrong in my case? Luckily the seller accepts returns, so it might not be a big thing to return them. I could also ask if he could change them to proper ones which will work. Thanks in advance!