I like CSound1's comments.
However it can seem that is almost completely random as to when an issue raises it head.
I tend to "Repair Permissions" as a first step and then Download and Installer of the COMBO version of the last Update that I did.
The Combo version obviously contains everything that has been updated since the Named version of the OS was released.
If those don't appeared to have worked resetting the PRAM often sorts the issue.
8:33 PM Friday; November 16, 2012
Please, if posting Logs, do not post any Log info after the line "Binary Images for iChat"
iMac 2.5Ghz 5i 2011 (Mountain Lion 10.8.2) G4/1GhzDual MDD (Leopard 10.5.8) MacBookPro 2Gb (Snow Leopard 10.6.8) Mac OS X (10.6.8), Couple of iPhones and an iPad "Limit the Logs to the Bits above Binary Images." No, Seriously
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