Hi,
What have you tried so far to sort this ?
I would restart the computer as a first step.
You may need to use the Activity Monitor (Applications/Utilities) to find and Quit the imagent item (it will be in lower case).
Any other history around this issue and/or error messages that have been seen would be useful.
9:39 PM Saturday; November 17, 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