I have an application, that also loads a custom component library as a RSL. Everything is setup from Flex Builder with the library as a RSL library project, and we're using the 'export release build' menu item.
However, when we deploy a new version of the application to live, we always get "Flex Error #1001: Digest mismatch with RSL http://foo.com/bin/componentLibrary.swf". I can't reproduce this locally though. If I clear the FireFox cache (or disable with the Web Developer extension) everything starts working. Watching the requests with FireBug, I can see a '200 OK' request for componentLibrary.swf, but this isn't seen by WireShark, or recorded in the Apache log. The headers for that request show the wrong last-modified and etag headers (compared to what is sent when the cache is off/cleared). I think Flash is caching the library RSL for much longer than it should (and this is why the request is only seen by FireBug). Has anyone fixed a similar issue before ? SDK is 4.1A, the server is Apache on Linux.