Combo Box Missing Scrollbars

On two new Dell laptops, I am having issues with AW.UI.Combo not displaying scrollbars in the drop-down. Works fine on all other systems.

The only thing I can think of is that the laptops in this case are widescreens and have their DPI factory-set differently than on normal desktops.

What can I do to solve this issue?

http://msdn.microsoft.com/library/default.asp?url=/workshop/author/dhtml/overview/highdpi.asp