It seems to work on the iphone emulator OK. You may need to use two finger scrolling on a real device though. Some devices require you tap into the area and then scroll.
You could add scrollbars for webkit with this code:
/* This is the element whose content will be scrolled if necessary */
box-shadow:0 0 2px rgba(0,0,0,0.15) inset;
Add the correct class of course and not just div.
I also read that -webkit-overflow-scrolling:touch; should make it a one finger scroll but haven't tested yet.