resize a gtkcombobox

[Andrea Zagli <azagli libero it>]

i have a gtkcombobox with a gtktreemodel

i initially fill the gtktreemodel with some strings, but while running  
the application these strings change but the gtkcombobox remains of  
the width of the longest of these strings and not of the width of the  
longest currently present in the model

is there a function to request the resize of the gtkcombobox each time  
i empty it and then i fill it again with new strings with different  
length?

thanks in advance