Norton Utilities solves an OS X startup problem

Rod Keller had a problem where when booting from Mac OS X on the internal drive of his iMac, the screen remained dark, even though the startup otherwise appeared to be normal (he could even login by typing his name and password). He started up from a Norton Utilities 6.0 CD and the screen sprang back to life. He then checked the drive with Norton and received this error:

"A major error was found in the Boot Blocks: The Shell name is bad."

He selected to fix this and then restarted. Mac OS X now booted normally, with the screen working again.