bug in wicket 1.4.12: AjaxButton does not update Panel models when opening a Modal Window

After a googling a bit about this bug, I couldn't find the written solution to this issue, described in this link:

http://apache-wicket.1842946.n4.nabble.com/Panel-not-refreshed-from-ModalWindow-via-Ajax-Button-td2235354.html

I didn't found this clearly specified in the wicket 1.4.13 changelog (that is why I'm posting this, so help fellow programmers googling the solution), but this issue is solved already. Just update to wicket 1.4.13.