http://bugs.winehq.org/show_bug.cgi?id=21095
--- Comment #6 from Dmitry Timoshkov dmitry@codeweavers.com 2009-12-21 09:35:47 --- (In reply to comment #5)
It's not clear at all if it's a standard scroll bar (then user32 would be appropriate choice) or a custom control. Do you have any clue Vitaliy?
Also (from the screenshot) it's not clear whether the culprit is a scrollbar.