Borderlayout BUG ??? problem resizing in firefox PLEASE HELP

<?xml version="1.0" encoding="UTF-8"?>
<zk xmlns="http://www.zkoss.org/2005/zul">
    <?taglib uri="http://www.zkoss.org/dsp/web/core" prefix="c"?>
    <?page title="Buenos Aires"?>
    <?link rel="shortcut icon" type="image/x-icon" href="img/cash_register.png"?>
    <?init class="buenosaires.webpages.initiators.IndexInitiator"?>
    <!---->
    <window id="wndIndex" onCreate="wndIndex.load();" use="buenosaires.webpages.IndexWindow"  width="100%" height="100%" onClientInfo="wndIndex.onClientInfo(event)">
            <borderlayout  style="background:#c5e6ef;" id="border" >
                <north flex="true" size="80px" maxsize="15" style="border: 1px solid #000000; background-image:url(${c:encodeURL('/img/header2.png') }); border: 'none'; background-repeat:no-repeat; background-position: right; background-color: #018cb7; " id="borderNorth"  margins="0,0,0,0">
                    <div>
                        <include id="incHeader" src="disposicion/header.zul" />
                    </div>
                </north>
                <west   size="150px" maxsize="150" border="none" title="Menu" splittable="true" collapsible="true"  margins="0,5,0,0" id="borderWest" visible="false" style="background:#d9f3ff;" >
                    <include id="incWest" src="disposicion/west.zul" />
                </west>
                <east  size="150px" maxsize="150" border="none" margins="0,0,5,0" splittable="true" collapsible="true"  title="Quick Links"  id="borderEast" style="background:#d9f3ff;" visible="false">
                    <include id="incEast" src="disposicion/east.zul" />
                </east>
                <center style="background:#e7f0f1;" border="0" id="borderCenter" flex="true">
                    <!--<window id="center"/>-->
                    <include id="incCenter" src="disposicion/center.zul" />
                </center>
                <south  size="40px" maxsize="40" border="none" style="background:#c0e4ed; border: 1px solid #000000;" id="borderSouth">
                    <include id="incButton" src="disposicion/button.zul" />
                </south>
            </borderlayout>
    </window>
</zk>