Doesn't look like you can actually scroll with a mouse either. I mean the scrolling itself works, but the dropdown closes on mouseup.
If they were a little faster I wouldn't mind them. It's funny that the scroll bar shows up before the menu is drawn over to it, but is that the only problem?
Edit: On a phone, the scroll bar doesn't show up, but the whole page scrolls while I'm trying to scroll in the menu. That's a problem.