The following files generated by the mozilla install is not owned by the package: /usr/lib/mozilla/chrome/overlayinfo/communicator/content/overlays.rdf /usr/lib/mozilla/chrome/overlayinfo/navigator/content/overlays.rdf /usr/lib/mozilla/chrome/overlayinfo/messenger/content/overlays.rdf /usr/lib/mozilla/chrome/overlayinfo/inspector/content/overlays.rdf /usr/lib/mozilla/chrome/overlayinfo/editor/content/overlays.rdf /usr/lib/mozilla/chrome/chrome.rdf The migth be more - I don't have the -mail and -chat packages installed.
That's normal. They are deleted when the package is uninstalled.