Comment 2 for bug 120654

Steps to reproduce:

1. Open firefox.
2. Open other app, like gcalctool.
3. Move this app over the address and tabs bars, like a sinusoidal wave, so that when you move it down you can see the address and tabs bars, and when you move it up they get covered.

Result: the borders of the address and tabs bars will look displaced.

I'll add a screenshot.