Tree doesn't redraw itself after axpand/collaps

[Daniel Kirsch]

Hi,
I'm using the tree-utils.js from chrome://venkman/content/ to create a 
tree from JavaScript.
I created a class which inherit from XULTreeView.

function PageTree() {
}
PageTree.prototype = new XULTreeView();
Now when creating the tree and expanding or collapsing a tree element, 
the tree doesn't get redrawn. If I force the tree to redraw by moving 
the window outside the visible area or showing another window in front 
of it, the new state will be shown correctly.

If I use XULTreeView directly everything works as expected.

Well, I simply don't understand what's causing this and what's the 
difference between an instance of the XULTreeView class or one subclass 
implementing XULTreeView.

I would be very happy for an explanation and/or a workaround how to use 
my own class inheriting from XULTreeView properly.

Thanks a lot
Daniel