There is a workaround on https sites when automatic update are activated, because the script is enable on all protocols.
The result is that Firefox report secured site as "partially encrypted" showing warning and red lock, instead of the green (EV) or blue URL bar.

Adding back (like in older version) "http://*" mask instead of only a "*" will work well.

Thanks, that was very helpful. It took me some time to realize that it was this script that caused the problem.

Thanks :)