HI,
With the Finder as the App listed in the Menu Bar use the Go Menu > Go to Folder
In the Dialogue box type (Or copy) the following
~/Library/Preferences
The ~ is short for Hard Drive Name/Users/(your account name)/Library/Preferences
Find the file called com.apple.ichat.Jabber.plist and drag it to the Trash
Restart iChat.
Does the account Log in properly now ?
8:51 PM Friday; October 26, 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