Creating gtk_tree_view with 2x editable cells and combo_box

[darekg11 <darekg11 tlen pl>]

Hi guys, I need to create a liststore with following columns:
editable entry|combo box|editable entry

I have been struggling with it for 4 hours now and when user chooses something from combo box or input string 
into cell it just doesn't save data.

I have been studing Editable Cell demo from gtk bundle but I still can't get it to work.