bBrowser and combobox

Hi,
i have a bBrowser with a field with this option:

oColonna:ViewValueAs := #ComboBox
oColonna:ValueTransformList := SELF:aEse

This display a list of value.

The seek text in this combobox is different from the seek of Vo combobox, 
because the search stop on the first character and not apply the
incremental 
seek.
It's a bug? It's normal? There is a solution?
Many thanks for any suggestion.

                                Francesco