Created attachment 418480 [details]
A picture showing the artifacts that appear when the Firefox window is scrolled.
Description of problem:
When a window is placed at the bottom of the screen and the contents are scrolled, artifacts appear.
Version-Release number of selected component (if applicable):
Happens once in a while.
Steps to Reproduce:
1. Place window below taskbar
2. Scroll contents of window
Artifacts appear as parts of the window's contents repeat.
No artifacts should appear
Artifacts disappear when the windows are redrawn either by selecting something else, moving the window, or resizing the window.
*** This bug has been marked as a duplicate of bug 589956 ***