I have the 1.8Ghz Macbook pro and bought new memory for it. The memory I bought was here: http://www.digi4me.com/product.php?productid=1687&cat=0&page=1 it seemed like a pretty good deal... Anyway, When I put the memory in the first thing I saw was the apple symbol as normal, but then it reset and kept looping. I took the old memory out and replaced it with the new, and I got nothing. Blank screen. The white light in front comes on but nothing else. Every other configuration I tried yielded the same results. At one point, turning on the computer would produce a steady blinking of the power light. Even going back to the original configuration of the 512 in slot 1 and the 1gb in slot two, which before produced a looping reset, now just gives a blank screen. So is there anything I need to do to get it to recognize the new memory? Is the memory I bought even compatible? Can I run a 1gb and a 512 or do they have to match? What else could be wrong?