When focusing the CKEditor in the test case below, the Listbox fires a onSelect event. This does not happen in 5.0.7. The whole problem is quite a serious issue if you rely on the onSelect event for further processing.

To reproduce, view the ZUL and click into the textarea.

<zk>
<window id="win" title="Test" mode="modal" border="normal" width="80%">
<listbox rows="1" mold="select" onSelect="alert(self)">
<listitem label="Test"/>
</listbox>
<ckeditor />
</window>
</zk>