gtktree inside combobox

[Guenther Meyer <d s e sordidmusic com>]

hi,

I have a question regarding a combobox:

what I currently have, is a filled gtktreemodel, and a gtktreeview, that works 
great in its own window.
but it should be possible to render the data into a combobox.
I played around a little bit, but all I got, is a combobox, that builds kind 
of treelike structure of popups with no content.
how can I attach or apply my renderers to this?

any help appreciated...
Guenther