I have an HTML page with a fixed-height div which should be scrollable (only vertically). In iOS 5 this can be achieved using:
overflow-y: a
I had the same problem in iOS 5.1.1 and it turned out to be due to an ::after pseudo-element with position: fixed that was on an element that contained the scrollable list exhibiting the "wrong scroll axis" behavior. Details here.
::after
position: fixed