I've found this ticket: http://tracker.zkoss.org/browse/ZK-2917 It seems that we have similar case within borderlayout but unfortunetelly this still doesn't work even we tried 8.0.1 and 8.0.1.1.

Please see attachments where we describe problem in details.

Description:

When the simple.zul is rendered initialy everything works well i.e. when we press the 'some command' button we can see correct notification. However when we relocate this to center by pressing 'move to center' button it doesn't - seems the this is the same problem as with
http://tracker.zkoss.org/browse/ZK-2917 in the logs we can see that some attributes are detached ....