I bought 2 1gb sticks of Omni tech ram for $160. I removed the apple ram and installed the first stick. Went in nice and smooth. The second stick would not go in. I tried both sides. Didn't go in. The first stick would go in either side. I made sure they were the same ram. They had all the same markings. I looked even closer and found that the one stick was a little wider than the other. It looked to be 2mm wider. I called Omni and they said they would send me 2 new ones. They said this never happened before. They were nice on the phone. Also, the first stick that went in worked fine and my macbook registered it. I tried 1gb and a 256 and it worked fine. I just have to send the 2 back within 10 days. They are sending new ram to me tomarrow. Its strange that the factory would mess up like that.