Stopped working on Firefox 15 Rated 5 out of 5 stars

I would never use automatic updates for anything; instead selecting them from Yast in OpenSUSE, which gives one the ability to revert: I'm not sure whether to go back to 14 yet because of this --- and the fact restored sessions on 15 jumble the tab order --- but I may...

The background is back to black, the image is still centred as I chose in the extension, but I'm sure that's just the Firefox default and the browser is ignoring the extension.

In developers' manic need to force their defaults on users --- witness the new no longer optional default of 'Tabs on Top' --- I'm wondering if Mozilla has had it with extensions that allow users' choice.

This review is for a previous version of the add-on (2.2).  This user has a previous review of this add-on.