I know you mean today is August 4th 2012.
Try a repair of avast:
Vista, win7 - Control Panel, Programs & Features, uninstall a program, select 'avast! Anti-Virus,' click the Uninstall/Change and select Repair, click next and follow.
You may need to reboot after the repair.
This has in the past resolved this out of sync issue between reported and actual version.