My 17" PB freezes constantly when attached to the power supply, they are random freezes, often during start-up, nearly always within 20 mins even if I don't touch it. When running on the battery it's solid as a rock. I've done all the usual stuff, permissions, fsck -y, reset the PMU, reset the NVRAM, restarted from the DVD and run the disc utility. I don't have a 3rd party utility, but the Apple Hardware check reveals nothing. Any ideas or should I throw it back at Apple? I read an article on Macfixit posted by a 17 user who'd had problems with his PSU not changeing it's colour and not charging properly, the guy at the Apple store said there was a known issue with the 17 PSU. Any thoughts?