Adorner being calculated incorrectly with a WrapPanel as ItemsPanel in a ListView

[Qwox]

I'm trying to add drag drop support in a ListView with a WrapPanel as ItemsPanel but the adorner gets calculated incorrectly when i scroll down while dragging.
After hours of searching for my mistake, I recognized that the same bug exists in the showcase app. It's reproducible with the "1.2.0-alpha0057" version by going to the ListView Bound Tab, dragging all items to the right side, shrinking the window down so that a scrollbar appears and dragging the first item down to the bottom.

Here's a .gif demonstrating it: