Prototype 1.6 : Element.viewportOffset (Opera 9.5)

In Opera 9.5b Element.viewportOffset doesn't give the same behaviour as in Opera 9.24.
Scrolling this test page should update the viewportOffset on the grey boxes.

Caused by a change involving scrollTop and scrollLeft found in the Opera 9.5b changelog

Fixed problem displaying maps on theaa.com caused by scrollTop working on both the html and body element simultaneously

Ticket & patch: #10486

position:
top: 300
left: 500

position:
top: 1400
left: 200

position:
top: 100
left: 1600