Scrollbar not showing in Panel

Hi,

I got a problem with the scrollbar not showing in the panel component in chrome. In firefox it is rendered correctly.

VerticalLayout (fixed width 250px) => Panel (size undefined) => Panel content = VL (size undefined) => Tree (size undefined)

The content of the tree is cut off on the right side. And the scrollbar is not showing (in chrome).

Chrome:
http://troll.ws/image/ec4fb764

Firefox:
http://troll.ws/image/b4ba4f6d

I am using Vaadin 6.8.8.

How can I fix this?

Thanx in advance.

Mihael