Comment 13 for bug 331365

notify-osd 0.8-0ubuntu4 steps to reproduce error:

login to gnome as normal user
set the panelt to the left and the right side (order is not important, I use 32pixel wide panels)
open 3 windows for example: firefox, gnome terminal, openoffice.org writer
open appearance
change effects to normal
change themes
change effects to none
wait half minute

(i install xfce but packages every dependency are ok
every package is ut to date)