Combo boxes in trunk (not sure about 2.14) have big left margins in the 
popup menu items (like this: http://www.gnome.org/~tvb/left_margin.png)

I found that with my system installed gtk+ 2.12.9 there was no left
margin in combo boxes.

To reproduce:

void main () {
  GtkWidget *window, *combo;
  gtk_init (NULL, NULL);
 
  window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
 
  combo = gtk_combo_box_new_text ();
  gtk_combo_box_append_text (combo, "text1");
  gtk_combo_box_append_text (combo, "text2");
 
  gtk_container_add (window, combo);
 
  gtk_widget_show_all (window);
 
  gtk_main ();
}

Note, Ive been packing my cell renderer and setting up my
model myself, the bug is there with or without the _text*() api.

Guess: may have to do with menuitem rtl/ltr code, which does
alot of ifs and calculates the toggle size request, not sure
if toggle size request is playing into the margin or not...