HI,
Once you get to OS X 10.8.2 which includes the Messages update to version 7.0.1 that becomes a common message back from the server.
I would check if the Mac's Serial Number is present.
About the Mac (in the apple icon menu) and click on the OS version line twice.
This thread is so old that the pics refer to version 7.0 and do not match the current iMessages account pane.
8:21 PM Monday; January 14, 2013
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