advanded combobox scrolling

[fornac]

I use an advanced combobox in the same way of the explorer demo. Everything works fine.
But i have a scrolling problem.
When i reduce the window browser the vertical scrollbar appears
an it's what i want, but when i use the scrollbar the textbox and the paging toolbar of the combobox don't move both, so the pagingtoolbar stays in the middle while the textbox move.

thanks for any help