Instead of using DIVs to avoid having the body element updated it is better to use h:panelGroup-s instead. This way the *_fixviewstate elements will be rendered at the same DOM tree level with the forms their scripts decorate.
<?xml version='1.0' encoding='UTF-8' ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:ace="http://www.icefaces.org/icefaces/components"
xmlns:icecore="http://www.icefaces.org/icefaces/core">
<h:head>
<title>#{title}</title>
<link rel="stylesheet" type="text/css"
href="./resources/css/template.css" />
<icecore:config mandatoryResources="linkButton dateTimeEntry dataTable dialog tabSet"/>
</h:head>
<h:body>
<h:panelGroup style="display: block;" class="header" align="center">
<ui:insert name="header">#{companyName}</ui:insert>
</h:panelGroup>
<h:panelGroup style="display: block;" class="topMenu">
<ui:insert name="menuItems" />
</h:panelGroup>
<h:panelGroup style="display: block;" class="contentBody">
<ui:insert name="tabItems" />
</h:panelGroup>
</h:body>
</html>
In my opinion a fix should be still found for the ace:dateTimeEntry component because body element updates are quite valid and are handled well both in Mojarra and Myfaces.
ICE-8562