[jQuery] Treeview: wrong class for lists in hidden divs

[jQuery] Treeview: wrong class for lists in hidden divs

When using the Treeview plugin in conjunction with the ui tabs I have
the following problem:
Lists that are placed in inactive tabs (not visible on pageload) get
the "expandable" class assigned but (as default) are displayed in its
expanded state, thus should have the "collapsable" class assigned.
Lists that are displayed in the active tab on pageload get the correct
class applied.
Any idea to fix this?