Applications won't quit, error 600, applications won't relaunch
But now many applications that I launch will not quit properly. Their windows close but they continue to appear active in the Dock. The Dock icons remain unresponsive. Yet when I try to relaunch the application, using "Recent Items," or by double-clicking an icon in the Applications folder, I get error 600 in this message: "The application xxxxx cannot be launched. -600"
Force Quit will not quit the applications. Nor will the machine not restart normally -- it must be forced to shut down. The it will restart, but the problems begin all over again. So -- quitting any of these applications requires a full forced restart in order to use them again. The problem is with native apps, like Mail, Software Update, Quicktime, iTunes, Safari, and so forth.
Any clues?
2.16 GHz Intel Core Duo Macbook Pro, Mac OS X (10.5)