I couldn't find anything among my old files that discuss this problem, although I'm sure for most of you its not a new issue. SYMPTOMS: (and what I did - right or wrong?): the whirling disk indicating the Mac is "working", no response when trying to access the Force Quit dialog box, shut down by pushing in the start up switch on the Quicksilver. Startup, then a repeat of the above, eventually just a Blinking question ?. Read a bit in Pogue's Mac OS X book and rebooted holding down the C key, somehow got to loading my OS X 3.9 disk, used Disk Utility- repair disc - it said Disk repaired - No problems ..... But, my happiness with this success has been dimmed with another Whirling disc (is that supposed to be a c or k?). I've wondered if some incompatibility is causing the problem? - I have about 40 gigs in use on the primary 60 gig drive ( I have moved music and iPhoto libraries to a new 2nd 120 gig drive - and used CCC to make a complete backup of the primary drive to an external LaCie 160 Firewire drive. Each time the problem occurred I had Entourage, Safari, Quickbooks, and sometimes iPhoto running - Thinking this is much running for my 500m of RAM, I've decided to only run the QkBks or the iPhoto at the same time but still had to resort to the Quicksilver start button to shut down and start again. Your ideas will be most welcome. Ray Hardy