Probably another instance of the 2.3 -> 2.4 -> 2.5 update hell. I've rebuilt the registry a dozen times now, and ran database updates through Drush. When I check for module updates, my site's showing that I have Rules 2.3 installed and *not* the 2.5 that's actually installed.
Any advice for this? Rebuilding registry/clearing caches seems to do nothing.