Problem with the stamp in gtktreeiter

[Matias Torres <torresmat gmail com>]

Hi
I'm trying to make a widget that works just like the address bar in 
epiphany (a combo box with completion)

The widget i'm workin on is a composite widget that uses 
GtkComboBoxEntry and GtkEntryCompletion.

This widget has a unique gtktreemodel that both, GtkComboBoxEntry and 
GtkEntryCompletion use, but when i try to set the active iter to the 
combo box based on the match-selected signal from the GtkEntryCompletion 
it tells me that the stamp of the iter is invalid.
How can i fix this?
If anyone knows where can i get a similar widget, please let me know

Thanks in advance, matias.