Thanks for the reply Marty, My firmware is 4.1.9, which I think is up-to-date, right? As far as RAM, not only did it pass all the tests, but I've tried with: - The original 64MB chip only - A Kensington 512MB chip only - Both All with the same results. Do you still think I should buy a third RAM chip and try that? - Mike >I recently had a similar situation, and it turned out the RAM was >bad...even though it passed all kinds of tests....ran fine in 9.2.2, >looked fine according to Tech Toll Pro 3 + Dimm first aid. At my Apple >dealer the manager said it wasn't a surprise, as OS X uses RAM more >completely. (?) Swapping in new RAM fixed it. >I would try that second, after confirming that the firmware is up to >date. > >-Marty