I believe that Firebug icon menu -> Options -> Reset All Firebug
Options
I am keen to fix this problem, but I couldn't reproduce it on my
machine.
Could you please send me your annotations.json file that is located
within a 'Firebug' dir that is under your Firefox profile folder
(check that it doesn't contains sensitive info before sending)
Also backup the file before you do "Reset All Firebug Options"
Also I need to know on what pages Firebug UI pops up
Ideally if you could report a new issue and attach the file
and the info to it?
Thanks!
Honza
P.S: Sebastian, do you know whether there is already a report for
this problem?