Borderlayout errors with gmap - Message: 'this.__mask' is null or not an object - IE8

[GoogleCodeExporter]

This simple zul causes a javascript error in IE 8:

<?xml version="1.0" encoding="UTF-8" ?>
<zk xmlns:zk="http://www.zkoss.org/2005/zul">
  <fwwindow id="${arg.windowId}"
            apply="com.pnl.fw.screens.map.freighttracker.FreightTrackerController"
            screenName="Freight Tracker"
            width="100%" height="100%">
    <zk:borderlayout>
      <zk:center border="none">
        <zk:gmaps id="gmap" mapType="map" lat="-30" lng="134" zoom="4" width="100%" height="100%" vflex="true" hflex="true" />
      </zk:center>
      <zk:west title="Search Criteria:" size="30%" flex="true" collapsible="true" splittable="true">

      </zk:west>
    </zk:borderlayout>
  </fwwindow>
</zk>

The error happens when you resize the west panel a few times:

Webpage error details

User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; 
SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; InfoPath.3; 
MS-RTC LM 8; FDM; .NET4.0C; .NET4.0E)
Timestamp: Thu, 3 May 2012 04:59:08 UTC

Message: 'this.__mask' is null or not an object
Line: 16
Char: 6258
Code: 0
URI: http://127.0.0.1:8081/FreightWeb/zkau/web/b6373861/js/zk.wpd

Using ZK v5.0.11

Original issue reported on code.google.com by therevil...@gmail.com on 4 May 2012 at 3:18

[GoogleCodeExporter]

Fixed since 2012-05-28.
Please try the latest freshly.

Original comment by benbai...@gmail.com on 28 May 2012 at 9:05

• Changed state: Fixed

[GoogleCodeExporter]

re-fixed, please try the latest freshly.

Original comment by benbai...@gmail.com on 5 Sep 2012 at 3:31

[GoogleCodeExporter]

re-fixed again,
remove bad patterns since 2012-9-6.

Original comment by benbai...@gmail.com on 7 Sep 2012 at 1:33