sarge: firefox: menu item turns blank when cursored over

[john doe <johndoe2k@gmail.com>]

After installing  "mozilla-firefox" package, go into gnome
desktop, launch firefox, the menu item turns blank (actually white)
when you move the cursor over it. See screenshot here:
  http://picserver.student.utwente.nl/view_image.php/66C1UCTV882Q/picserver.png
This problem doesn't happen to other gnome applications such as gedit.
Anybody else has a similar problem? And any clue how to fix it? I
probably should just download a off-shelf copy directly from
mozilla.org.

-jd