mozilla/MozStumbler — pull request #1056 by garvankeeley (2014-10-21 15:22:16+00:00)
Title: Delete stumbles on 400 (bad request) errors only

In theory other errors, particularly 404 can be temporary (and incorrectly) be returned by proxies.
Due to complaints about data disappearing I am trying to minimize the possibilities of stumbles being disposed.