We have an application that uses a ice:panelPopup to display a Popup Window which our user uses to enter search parameters. This searchDialog contains fields (into which search criteria is entered) and buttons... most important of which is the "search" button that runs the search. If an error occurs when running the search, a message is displayed in another ice:panelPopup. This is the scenario where we have panelPopups that are stacked on top of each other. The scenario is

1) Display the search popup
2) Enter criteria that causes an error and click the search button
3) An error message is displayed, in a new popup dialog that is visually "on top" of the search dialog. Click Ok to close the message dialog
4) Enter different criteria that will cause an error and click the search button.
5) An error message is displayed, in a new popup dialog that is visually "on top" of the search dialog.

In Firefox, this works fine. In IE (version 8), step 5 never occurs. Nothing visually happens until the user clicks a button to close the Search dialog. At this point, the second message dialog is visible. So, the second message dialog was displayed, but it was under the Search Dialog.