In the past two days, I've twice had my screensaver get "stuck." The computer doesn't go into sleep mode (as it usually does, with a black screen), and clicking the mouse or hitting a key on the keyboard doesn't dismiss the screensaver.
Both times, with a lot of futzing around, I've finally been able to get it to go away, but I never can tell what did it. The first time it went away shortly after I unplugged and plugged back in my keyboard, and turned the bluetooth Mighty Mouse off and back on.
My Mighty Mouse periodically just spontaneously loses connection, and I can't tell, when the screensaver is hung, whether that has happened or not, but turning it off and back on always restores the connection (after it syncs back up), and I can't understand at all why my keyboard no longer dismisses the screensaver, which it has always done before this started.
I can't find anything anywhere about anyone else having this problem. Does anybody know what might be causing it?
Right after the problem happens again, open Console.app and open "All Messages", located under "Log Database Queries". Copy everything within the time period that the problem was occurring (IE: from when your screen saver starts to when you manage to dismiss it), and paste it here.