GtkCellRendererCombo questions

["Vadim Berezniker" <vadim berezniker com>]

1) Is there any way to add a "separator" item into the list?

2) Is there any better way to differentiate which item was selected in
the combo?
Right now, by hooking into the changed event, the callback simply
receives the text of the item.
I want to at least know which row in the backing store was selected. (So
that I can store/retreive other information in the store)