Mac App Store says I have an update, but when I go into the Store, it says I have no updates. I close it out and the Mac App Store icon in the dock still has an indication "1" that I have an update. What gives?
Absolute nuisance. It's probably a left over from your last update.
App store says it still have one...: Apple Support Communities
The MAS gets it's app info from Spotlight. I suggest reindexing your Mac.
Retrieving data ...