Please test after taking each of the following steps that you haven't already tried. Stop when the problem is resolved. Back up all data before making any changes.
1. With the Updates tab selected, select
Store ▹ Reload Page
from the menu bar. It may take a minute or so for the update list to refresh.
2. Open a search window by pressing the key combination command-F in the Finder. Select This Mac as the search scope and search for the app(s) in question by name. Delete any outdated copies that you find.
3. If the search results seem to be inaccurate, rebuild the Spotlight index. If you try to search now, there will be an indication that indexing is in progress.
4. Triple-click anywhere in the line below on this page to select it:
~/Library/Containers/com.apple.appstore
Right-click or control-click the line and select
Services ▹ Reveal in Finder (or just Reveal)
from the contextual menu.* A folder should open with an item selected. Quit the application if it's running. Move the selected item to the Trash. Relaunch the application and test.
*If you don't see the contextual menu item, copy the selected text to the Clipboard by pressing the key combination command-C. In the Finder, select
Go ▹ Go to Folder...
from the menu bar and paste into the box that opens by pressing command-V. You may not see what you pasted because a line break is included. Press return.
5. If the above steps don't resolve the problem, quit each app in question and uninstall it by following the instructions on this page. Alternatively, you can drag it from the Applications folder to the Trash, and empty. The data files you created will be preserved. Verify in Spotlight that there are now no copies of the app on your system. Download it from your Purchases history in the App Store.
