faces navigation rules not working for two portlets on portal page

I'm trying to write some JSF portlets within one portlet application
but encountered some problems concerning navigation rules when I
put more than one JSF portlet per portal page.

When I put just one portlet on my page everything concerning the
navigation rules (with <h:commandButton action="p1next" value="go on"
/> stuff) works fine and I get to the next view.

But when I put a second faces portlet on the page navigation and invoking
actions on backing beans in the second portlet just doesn't work at all.

If I remove both portlets and put the second portlet on the page again (so that
I'm having just one portlet again) this portlet works fine as well. So I assume
that navigation settings in faces-config.xml must be correct. It has
something to do
with the arrangement of two faces portlets on the portal page so that
the second one
stops working as expected.

I also tried to use distinct IDs for all ui-components and also
distinct <from-output>-values but that doesn't help

Thanks
zeroconf

Attached are the important parts of my web.xml, faces-config.xml and portlet.xml

web.xml
============================

<?xml version="1.0"?>
<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web
Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd">

<web-app>
<display-name>PROJECT_NAME</display-name>

<context-param>
<param-name>company_id</param-name>
<param-value>liferay.com</param-value>
</context-param>
<context-param>
<param-name>javax.faces.STATE_SAVING_METHOD</param-name>
<param-value>client</param-value>
</context-param>
<context-param>
<param-name>javax.faces.application.CONFIG_FILES</param-name>
<param-value>/WEB-INF/faces-config.xml</param-value>
</context-param>
<listener>

<listener-class>com.liferay.portal.servlet.PortletContextListener</listener-class>
</listener>
<listener>

<listener-class>org.apache.myfaces.webapp.StartupServletContextListener</listener-class>
</listener>
<servlet>
<servlet-name>PROJECT_NAME</servlet-name>

<servlet-class>com.liferay.portal.servlet.PortletServlet</servlet-class>
<init-param>
<param-name>portlet-class</param-name>

<param-value>org.apache.myfaces.portlet.MyFacesGenericPortlet</param-value>
</init-param>
<load-on-startup>0</load-on-startup>
</servlet>
<servlet>
<servlet-name>FacesServlet</servlet-name>
<servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>PROJECT_NAME</servlet-name>
<url-pattern>/PROJECT_NAME/*</url-pattern>
</servlet-mapping>
<taglib>
<taglib-uri>http://java.sun.com/portlet</taglib-uri>

<taglib-location>/WEB-INF/tld/liferay-portlet.tld</taglib-location>
</taglib>
</web-app>

faces-config.xml:
==================

<?xml version="1.0"?>
<!DOCTYPE faces-config PUBLIC "-//Sun Microsystems, Inc.//DTD
JavaServer Faces Config 1.1//EN"
"http://java.sun.com/dtd/web-facesconfig_1_1.dtd">

<faces-config xmlns="http://java.sun.com/JSF/Configuration">
<factory>

<faces-context-factory>org.apache.myfaces.context.MyFacesContextFactoryImpl</faces-context-factory>
</factory>

<!-- navigation for JSF portlet 1 -->
<navigation-rule>
<from-view-id>/jsp/jsf1/index.jsp</from-view-id>
<navigation-case>
<from-outcome>p1next</from-outcome>
<to-view-id>/jsp/jsf1/n1.jsp</to-view-id>
</navigation-case>
</navigation-rule>
<navigation-rule>
<from-view-id>/jsp/jsf1/n1.jsp</from-view-id>
<navigation-case>
<from-outcome>p1back</from-outcome>
<to-view-id>/jsp/jsf1/index.jsp</to-view-id>
</navigation-case>
</navigation-rule>

<!-- navigation for JSF portlet 2 -->
<navigation-rule>
<from-view-id>/jsp/jsf2/index.jsp</from-view-id>
<navigation-case>
<from-outcome>p2next</from-outcome>
<to-view-id>/jsp/jsf2/n1.jsp</to-view-id>
</navigation-case>
</navigation-rule>
<navigation-rule>
<from-view-id>/jsp/jsf2/n1.jsp</from-view-id>
<navigation-case>
<from-outcome>p2back</from-outcome>
<to-view-id>/jsp/jsf2/index.jsp</to-view-id>
</navigation-case>
</navigation-rule>

</faces-config>

portlet.xml
=============================

<portlet>
<portlet-name>jsf2</portlet-name>
<display-name>jsf2</display-name>

<portlet-class>org.apache.myfaces.portlet.MyFacesGenericPortlet</portlet-class>
<init-param>
<name>default-view</name>
<value>/jsp/jsf2/index.jsp</value>
</init-param>
<supports>
<mime-type>text/html</mime-type>
</supports>
<portlet-info>
<title>jsf2</title>
<short-title>jsf2</short-title>
<keywords>jsf2</keywords>
</portlet-info>
</portlet>