com/webx?128@756.oAGIaf7Q1cx.185080@.68a8e9bb (link dead?) http://discussions.info.apple.com/webx?7@975.XP8XaxgHUOR.0@.
Apparently this is a huge problem, apple seems to be in denial about it, and they’re charging ~350 dollars to fix it. My computer is working fine off the ram in the top slot.. and I can’t afford to send it in. After reading through the postings on the above links it looks like this is a problem that can actually crop if in any powerbook with both ram slots filled. This problem started happening when 10.3.9 was released, and persists through the current releases of Tiger.