Bug 650716 contains the apport data from another instance of this crash/bug, reproduced immediately after the one in this report. I thought it might be useful for comparison's sake. It seems this might be the cause (from .xsession-errors):
(nautilus:1323): Gtk-CRITICAL **: IA__gtk_widget_set_child_visible: assertion `GTK_IS_WIDGET (widget)' failed (nautilus:1323): Gtk-CRITICAL **: IA__gtk_widget_size_allocate: assertion `GTK_IS_WIDGET (widget)' failed
Bug 650716 contains the apport data from another instance of this crash/bug, reproduced immediately after the one in this report. I thought it might be useful for comparison's sake. It seems this might be the cause (from .xsession-errors):
(nautilus:1323): Gtk-CRITICAL **: IA__gtk_ widget_ set_child_ visible: assertion `GTK_IS_WIDGET (widget)' failed widget_ size_allocate: assertion `GTK_IS_WIDGET (widget)' failed
(nautilus:1323): Gtk-CRITICAL **: IA__gtk_