In February 2006, Mike Connor, representing the Mozilla Corporation, wrote to Debian and informed them that Mozilla did not consider the way in which Debian was using the Firefox name to be acceptable.[11] Connor confirmed that the Mozilla Corporation was revoking the previous agreement with Debian which allowed them to use the Firefox name. Further messages from Mike Connor clarified Mozilla’s current policies: “Yes, if you are shipping a browser called Firefox, we should be signing off on every deviation from what we ship.”; and “If you are going to use the Firefox name, you must also use the rest of the branding.”

As Debian could not use the logo because its license did not conform to the Debian Free Software Guidelines, it could thus not use the Firefox name under Mozilla’s revised guidelines. In addition, Debian freezes its releases on a long term basis and later patches software in the frozen stable releases for newly-discovered security issues. Under the revised guidelines, in order to use the Firefox name, it would have been required to seek approval from the Mozilla Corporation for all security patches.

I think that maybe it’s both.