585102 - Strange line in appears below title bar when focus is moved outside Firefox

Status: RESOLVED DUPLICATE of bug 579250

(Firefox :: Theme, defect)

Description

[Paul Simon]

User-Agent:       Mozilla/5.0 (Macintosh; Intel Mac OS X 10.5; rv:2.0b2) Gecko/20100720 Firefox/4.0b2
Build Identifier: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.5; rv:2.0b2) Gecko/20100720 Firefox/4.0b2

Whenever I take the focus away from Firefox a line appears between the title bar and tab/location bar (depending on what's on top). And by taking focus away I mean:
 - Clicking the help menu,
 - Clicking anything in the upper right corner of the screen (like the battery, clock, AirPort etc.),
 - Right clicking or dragging an icon in the dock,
 - And perhaps something more, but you get the idea.

And it won't go away by itself, so you'll have to switch to another tab, or if you're lucky, just wait (it's rather unpredictable).

Reproducible: Always

Steps to Reproduce:
1. Steal the focus from Firefox by either
 - Clicking the help menu,
 - Clicking anything in the upper right corner of the screen (like the battery, clock, AirPort etc.),
 - Or right clicking or dragging an icon in the dock,
 - And perhaps something more, but you get the idea.
2. (Click the Firefox window.)
Actual Results:  
A line appears below the title bar dividing it from the rest of the tool bars.

Expected Results:  
Nothing.

I've only encountered this using the default theme in v4.0b2.

Comment 1

[Markus Stange [:mstange]]

This will be fixed in Beta 3.