Opera Mobile incorrectly calculates position: fixed

I have a interesting problem with position: fixed in Opera Mobile 11:

Test page: http://dl.dropbox.com/u/841468/testcase/opera/fixed.html

The red <div> should stay fixed on top. If I scroll page down, element moves a bit from top edge of viewport (exactly 93px in device pixels); but if I scroll up, element returns to correct position.

(Screenshot on HTC Desire):

Screenshot on HTC Desire

My findings:

Changing zoom level didn't help and didn't change element position from top edge.
It works correctly in Opera Mobile emulators (both 10.1b and 11)
Setting or removing "top" / "left" properties didn't help
Setting "z-index" or "display" properties to some value didn't fixed it
It shows this behavior even when I move viewport with window.scrollTo(x, y)
Setting "zoom" to "reset" didn't work
Mouse events get through this element to element under it (if it is in that incorrect position)
Trying IE hacks didn't work :)

Thanks

Solution

This issue has been fixed internally, and the Opera Mobile 11.5 version should roll out with this working correctly.