I recently ran into an issue during a full restore of a Time Machine backup where the Launchpad layout would not be restored, and instead returned to a default layout. If you're like me and have put a lot of effort in customizing the layout, it's a bummer having to do all the work again, especially since one would expect a full restore from Time Machine actually restores *everything* (but that's discussion for another thread, I guess).

At first, I assumed Time Machine didn't back up everything but, as it turns out, the files are present but not restored during a full restore operation. Luckily, there's a way recover this manually. You can also do this if for some reason Launchpad is corrupt  ...