The Mac App Store in OS X 10.6 not only is a source of new applications, but also provides updates for the apps you have installed through the store. The store should detect the installed applications and notify you when an update is available, but for some people this does not work as expected and updates may not show as being available.
Recently a MacFixIt reader wrote in to us regarding this issue, and outlined a fix that was suggested by an Apple representative.
The problem with the App Store updates may be rooted in the store's use of Spotlight to locate installed applications. In order for the store to locate the applications, the Spotlight index needs to be working properly. As a result, one approach to fixing the problem is to force a rebuild of the system's Spotlight index. To do this, follow these steps:
- Go to the Spotlight system preferences.
- Go to the Privacy tab.
- Add your boot drive ("Macintosh HD") to the privacy list and close the preferences.
- Open the preferences again and remove your hard drive from the list.
- Reboot the system.
With the system freshly restarted, wait for the spotlight index to rebuild (the spotlight menu will have a pulsing dot in it while this is happening). Once Spotlight has fully indexed the drive, open the Mac App Store again and try updating your applications again, and if that was the problem then the updates should appear properly.