Problemas "tag sem referencia": JSF + Facelets + Richfaces

Estou desenvolvendo uma aplicação com JSF + Facelets + Richfaces e estou tendo problemas.
Estava usando JSP antes e estava tudo ok com meus testes.

O problema começou quando comecei a usar o facelets. No firefox dá um erro, as vezes sim,
as vezes não de “tag sem correspondencia”. As vezes acontece quando carrego a pagina pela
primeira vez, as vezes quando clico no htmlMenuItem do richfaces.

Agradeço se puderem colaborar.

Segue o faces-config.xml, web.xml e o index.xhtml que está dando problema.

index.xhtml

<?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:f="http://java.sun.com/jsf/core"
      xmlns:a4j="http://richfaces.org/a4j"
      xmlns:rich="http://richfaces.org/rich">

    <head>
    </head>
    <body>
        <h:form>
            <rich:toolBar style="position:absolute; top:0px; left:0px;" >
                <rich:menuItem value="Teste" action="null"/>
            </rich:toolBar>
        </h:form>
        
    </body>
</html>

faces-config.xml

<faces-config version="1.2" 
    xmlns="http://java.sun.com/xml/ns/javaee" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-facesconfig_1_2.xsd">

</faces-config>

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

    <context-param>
        <param-name>org.richfaces.SKIN</param-name>
        <param-value>blueSky</param-value>
    </context-param>

    <context-param>
        <param-name>org.ajax4jsf.VIEW_HANDLERS</param-name>
        <param-value>com.sun.facelets.FaceletViewHandler</param-value>
    </context-param>

    <filter>
        <display-name>RichFaces Filter</display-name>
        <filter-name>richfaces</filter-name>
        <filter-class>org.ajax4jsf.Filter</filter-class>
    </filter>

    <filter-mapping>
        <filter-name>richfaces</filter-name>
        <servlet-name>Faces Servlet</servlet-name>
        <dispatcher>REQUEST</dispatcher>
        <dispatcher>FORWARD</dispatcher>
        <dispatcher>INCLUDE</dispatcher>
    </filter-mapping>

    <context-param>
        <param-name>javax.faces.DEFAULT_SUFFIX</param-name>
        <param-value>.xhtml</param-value>
    </context-param>

    <servlet>
        <servlet-name>Faces Servlet</servlet-name>
        <servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>Faces Servlet</servlet-name>
        <url-pattern>/faces/*</url-pattern>
    </servlet-mapping>
    <session-config>
        <session-timeout>
            30
        </session-timeout>
    </session-config>

    <welcome-file-list>
        <welcome-file>faces/index.xhtml</welcome-file>
    </welcome-file-list>

</web-app>