We have a dock site with two tool windows in it.
The dock site is made children of a canvas with the first tool window docked permanently in it.
The second tool window is made to float around anywhere.
With this arrangement in XBAP, the second tool window does not resize properly. We are able to resize a bit if we float the second window away from the first window but beyond a certain width, it does not resize.
Same arrangement works fine in desktop.