My macbook book pro is having some weird drive/boot issues. tried to boot and got only a grey screen, no chime or anything else. ran disk utility from the startup CD and it won't even see the drive. so, popped the drive out, installed in external firewire case, and checked the drive on another computer and it showed up and all files seemed fine. So, tried a firewire boot on the macbook pro, and it booted up just fine. popped the drive back into the macbook pro, and again, nothing. wont boot, and when booted from startup CD, the drive won't show up. any ideas on this?