Gnome 3 and crashing

I've really been liking Gnome3, but there's this nagging crashing issue that's been driving me buggy.  In my error logs, I get stuff like "widget outside GTKWindow" and other odd GTK errors. 

After googling for a while and getting nowhere, I did stumble upon a hint where somebody had replaced gdm with kdm.  I tried it and lo and behold, I can run git-cola without it crashing my session. 

I do get errors still, like: Gtk-Message: Failed to load module "canberra-gtk-moduleanberra-gtk-module", but hey, as long as it doesn't crash, I'm fine!