That bug has been described on https://bugzilla.ubuntu.com/show_bug.cgi?id=22293

"Hi,

I have found a Gtk+ example that causes a segmentation fault when using Ubuntu
Breezy. I am using Gtk+ version 2.8.6-0ubuntu2.

It appears to be when a Gtk window has it's resize mode set to
gtk.RESIZE_IMMEDIATE and a GtkComboBox is packed into it a segmentation fault is
generated. It does not occur using a GtkLabel. The same code in C also generates
the segmentation fault.
...
The program runs if you:
quote out the line "window.set_resize_mode(gtk.RESIZE_IMMEDIATE)" OR
replace "combo = gtk.ComboBox()" with "combo = gtk.Label('test')"

The equivalent C program that produces the same problem:
(compile with "gcc -g -Wall `pkg-config --cflags --libs gtk+-2.0` test.c -o test")
<snip>
#include <gtk/gtk.h>

int main(int argc, char **argv)
{
   GtkWidget *window, *combo;

   gtk_init(&argc, &argv);

   window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
   gtk_container_set_resize_mode(GTK_CONTAINER(window), GTK_RESIZE_IMMEDIATE);

   combo = gtk_combo_box_new();

   gtk_container_add(GTK_CONTAINER(window), combo);

   gtk_widget_show_all(window);

   gtk_main();

   return 0;
}
</snip>

Replacing the combo box with a label or removing the resize mode causes the
program to run successfully."