Pls check first the Build from your WSUS. In WSUS-FAQ No. 44 you will find more Informations about the place you will find the Build and which Build you have to have:
http://wsus.de/faq
After you have installed Build .274, pls restart WSUS and try again.
http://wsus.de/faq
After you have installed Build .274, pls restart WSUS and try again.