Hi all, This is the oddest iMac problem I've ever experienced. I was hoping someone could give me a hint or two. I can't try anything until I get home tonight - but I thought I'd post now while I have access to a working computer... I was surfing around the internet last night, and just before I headed off to bed, my iMac stopped reacting to user input. You could mouse around (even mousing over the dock) but clicking on anything wouldn't work. I have a "mighty mouse" that I've had no real trouble with up to this point - and I don't think it is the mouse - but it could be I suppose. Any dock item you mouse over will "tooltip" but not respond to click. The keyboard is likewise unable to invoke any response except for the "reboot" sequence. Any ideas out there? Is there something I am missing?