Comment 4 for bug 927031

Me too. I upgraded from 11.10 to 12.04 (x86_64). In 11.10 nothing happen.

I found out, that notification-daemon only crashes, if a gtk-2.0 theme is applied. On a normal installation of Lubuntu 12.04, a theme named "Lubuntu-default" is selected (which has also a gtk-3.0 directory). If I change to a gtk-2.0 only theme like "Redmond", notification-daemon chrashes on first popup.