I have a number of Dropdowns in a Splitter Pane.  Some of them are dynamically populated with enough items to require a scrollbar when the DropDown is opened.  I can select any item that is visible when the dropdown first opens.  However, any attempt to scroll to an item and select it fails.  As the cursor moves from the scrollbar to the dropdown area it returns to the top of the list of items.  There are no client side events bound to the control.

Any idea what is causing this and how to fix it?