background property not showing on CSS panel

[Földes László]

I was searching for the CSS settings of a background image, but couldn't find it in Firebug, even with Inspector. I headed to my friend who used Chrome, I checked there and that element showed up, along with the URL and other data as well.
I tried Firefox's own development tool and there it was.

What is the problem here, why the 'background' element is not showing in Firebug in body #settings-bottom .setting-icon?

[Sebastian Zartner]

From a first sight this looks like a bug, though without the actual code it's hard to say what's the problem and much less to fix it. So please attach or link to a simple test case, where this problem can be reproduced.

Sebastian