I have a PowerBook 17" 1.5 plus a 23" Cinema display. I decided it was time to max out the RAM (had 512) so i got 2 x 1GB sticks and installed them. When I booted it up it almost immediately shut down. Thinking it was the new RAM I pulled it and put the original back in... same thing. So I unplugged everything and booted again and everything was fine. I started plugging things in one at a time. When I got to the external display it went black then both screens lit up but there was also a box asking if I wanted to shutdown, restart etc. Before I could even click a button it shut down on me. It's weird because it recognizes the display but automatically shuts down. I'm trying to figure out whats going on. I had this thing torn apart to change the drive about 2 weeks ago and everything has been humming along perfectly. HELP!