My 1.5 year old Powerbook has two memory so-dimms (each 512 MB). Recently, the lower slot's memory stopped being recognized. I tried reseating the so-dimm and it fixed the problem briefly, but soon stopped recognizing that so-dimm again. I then tried swapping the two so-dimms, and while that fixed the problem briefly, eventually the _same_ slot's memory wouldn't be recognized. It's clear that the memory itself is not the problem. Is there anything that can be done to fix this, or am I looking at a bad motherboard? Also, since I don't have AppleCare, what's the best way to deal with Apple Support (i.e. can I just pay for the repair without paying for a tech support incident file)? Thanks for your help!