An error has occurred
My App store app recently started telling me there were updates to install. When I checked, it showed me that Numbers had an update. However, when I tried to install it I got the message "An error has occurred" and on checking I discovered that my Numbers app was already up to date. I can't get rid of the update message and I'm regularly being told that I need to update this app. Suggestions on how to cure this would be welcomed.
MacBook Pro, OS X Mountain Lion (10.8.2), also: 16 GB iPhone 5