I got two 2GB ram sticks from Crucial, to replace the original 2 512MB sticks. The black MacBook will not boot after installation of the new ram. I am certain that I have the right memory, that ram is firmly seated, and that both 2GB sticks are good because when I take one out and replace the OM 512 stick back in the laptop (slot0) then macbook boots fine and system profiler reads 2.5GB ram regardless of which 2GB stick I have in (slot1). I've dug up the specs, and Apple themselves state that this model 3,1 supports 4GB, and others have successfully installed 6BG using one 2GB and one 4GB. Is there anything I can try to make use of both 2GB new memory sticks? The specs in detail is the black 2.2GB core2duo 13" late 2007 "Santa Rosa". Thanks in advance.