I am experiencing a strange problem: after I installed a bunch of updates, the Mac AppStore badge was not reset. When I go to "Updates", I get the message "no updates available". I tried to
- delete the AppStore cookie
- rebuild the Spotlight index (found a recommendation to do so somewhere)
- logged out and in the AppStore
- delete some of the updated Apps and re-installed them
without any effect. Today, I got an update for another application; the update count was incremented and was not reset again.