Have just beaten Ulfric, got back to Whiterun and discovered that Arcadia's Cauldron has disappeared - apart from the door and the sign, and it has been replaced by nothing just a gaping hole. It can be seen at:

http://www.aotonline.me.uk/ScreenShot3.jpg

Go outside of Whiterun, save your game, shut down and restart. That may help.

I'm assuming the door still takes you inside?

Sorry, I didn't get back to you to thank you. It worked. Thanks.