A few times after I've downloaded an app from the Amazon Appstore, I get an error pop-up similar to the following when opening the app:
There was a problem verifying this application. Please download it again.
It hasn't occured on the first launch of an app, but rather the second (or possibly later). Uninstalling it and then downloading it again always solves the problem; it never occurs again for the same app (except Gentle Alarm. I couldn't shut it off because Amazon wouldn't let the app run, just the service. Gah).
My question is, why does this happen? If the app works fine, it shouldn't be corrupted, so I don't see why it couldn't be verified (especially since it was verified fine on the first launch). Is there some extra data downloaded? Is it managed by the app or the appstore? (I.e., would clearing data for one, the other, or both solve the issue without needing to re-download?)