iOS5 - overflow scrolling horizontally is controlled by vertical touch

Question

Possible Duplicate:
Issue with scrolling in iOS 5 using -webkit-overflow-scrolling

I have a div with a wider child element which is set to -webkit-overflow-scrolling: touch.

On page load, in landscape orientation, to scroll the div horizontally you must move your finger vertically up and down the div. So moving up scrolls left and down scrolls right. After switching to portrait and then back to landscape orientation scrolling works as expected - horizontal touch movements scroll horizontally. With -webkit-overflow-scrolling set to auto I dont see this problem. Googling for this returns no results, has anyone else encountered the behaviour?

My css:

#stream-container-outer {
    width: 925px;
    margin: 0 auto;
    overflow: auto;
    -webkit-overflow-scrolling: touch;
}
#stream-container {
    width: 900%;
}