I had a few apps originally purchased through the App Store that got corrupted. I removed them with the intent of re-installing them from the App Store, but it seems that the App Store thinks they're still/already installed. The action button is disabled. I found [a related question](http://apple.stackexchange.com/questions/7075/how-can-i-reinstall-an-application-that-the-mac-app-store-thinks-is-installed-alr), but the solution didn't work for me.

The app doesn't exist in either `/Applications` or `/Downloads`. Any ideas what I might be able to do to re-download the app?

Thanks.