Currently Being ModeratedOct 25, 2012 2:00 PM (in response to ymshelanu)
I had a similar problem and tried the reindex Spotlight fix and this one: http://www.ngpixel.com/2011/06/25/mac-app-store-you-have-updates-available-for-t he-other-accounts-bug/ and tried the solution by commenter Renso on the same site. Nada.
My problem was that all the apps that would not update were not in the Applications folder. For some reason they were actually on another drive. It seems the App Store app scans all the drives and because the apps were not in their original location it produced this misleading error message.
This is such a poor error message—obviously a lazy programmer who couldn't be bothered specifying a real message pertinent to the actual problem.