Some time ago, I bought 2x512Mb sticks of RAM from OrcaLogic for my Powerbook. About 3 weeks after installing it, the Powerbook wouldn't stay on when it was booted up. It'd chime, then spin up and suddenly switch off. Suffice to say, I removed the RAM sticks and put the Apple ones back in. This didn't fix it. It was already out of warranty (no AppleCare) and Orca's policy is such that as the RAM worked to start with it wasn't technically faulty. Anyway, I did all the usual stuff like resetting PRAM, resetting the PMU etc etc and then tried to boot it up in Target Firewire HD mode. It worked. Then I discovered something really strange that I have been using ever since - to get the computer to start, I have to hold down the keys Shift + Option + Apple + Backspace just after the chimes for about 4/5 seconds. If I do that, it starts with no problems whatsoever. Does anyone know how the hell this works??? I'm stumped, but it's a damn good security system. Dogsbody.