17" SR mbp running 10.5.2, installed latest efi firmware update and mbp still refuses to shut down properly. now it's gotten to the point where more often than not when i try to shut down or restart, it would start to go through the process, then the screen would just go blank but machine won't shut down or restart, forcing me to hit the power button for hard reset. did not have this problem before when running Tiger, but it started ever since Leopard, hoped 10.5.2 would solve it but it didn't. read somewhere that it might be some processes hanging up the process but shutting down growl, itunes helper, google updater, coversutra, quicksilver, etc. still doesn't guarantee that it'll shut down properly. tried resetting the pram, repairing permissions, etc. but nothing's worked. any ideas?