Exception when deploying a JSR 286 portlet into WebLogic+WebCenter 11g

I get the following exception when deploying a JSR 286 portlet into Oracle WebLogic Server 11g (to deploy it later in Oracle WebCenter 11g):

<19-ene-2010 13H32' CET> <Error> <oracle.portlet.server.containerimpl.PortletApplicationImpl> <BEA-000000> <Error al procesar el archivo "/WEB-INF/portlet.xml" en la lÝnea 6 columna 68.
org.xml.sax.SAXParseException: cvc-elt.1: Cannot find the declaration of element 'portlet-app'

The error message is in spanish. It means:

"Error processing the file "/WEB-INF/portlet.xml at line 6 column 68"

The portlet.xml of my portlet seems to be correct and I've deployed it in other portal servers. So I don't understand the error message.

This is the portlet.xml of my portlet (eclipse XML validator said it was a valid XML)

<?xml version="1.0" encoding="UTF-8"?>
<portlet-app version="2.0"
    xmlns="http://java.sun.com/xml/ns/portlet/portlet-app_2_0.xsd"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/portlet/portlet-app_2_0.xsd
                        http://java.sun.com/xml/ns/portlet/portlet-app_2_0.xsd"
    xmlns:dnd="http://www.denodo.com/widget/portlet/portletjsr286">

    <portlet>
        <description>Test Inter Portlet Communication (JSR286)</description>
        <portlet-name>Test IPC</portlet-name>
        <display-name>Test IPC</display-name>        
        <portlet-class>com.denodo.ipc.TestIPCPortlet</portlet-class>       

        <supports>
            <mime-type>text/html</mime-type>
            <portlet-mode>VIEW</portlet-mode>
        </supports>

        <supported-locale>en</supported-locale>
        <resource-bundle>PortletMessages</resource-bundle>

        <portlet-info>
            <title>Test IPC</title>
            <short-title>Test IPC</short-title>
            <keywords>Test IPC,Denodo</keywords>
        </portlet-info>

    </portlet>

</portlet-app>

How do I deploy my portlet

1. I convert my portlet into to a WSRP portlet by executing java -jar wsrp-pr开发者_如何学Goedeploy.jar source EAR target EAR as explained in http://download.oracle.com/docs/cd/E12839_01/webcenter.1111/e12405/wcadm_portlet_prod.htm#CHDECJHI)
2. I try to deploy it into WebLogic with the WebLogic Console and I get this exception.

My Environment

WebCenter Suite (11.1.1.2.0) + WebLogic Server (10.3.2) downloaded from the oracle.com. Default configuration

S.O: Windows XP SP3

Thanks in advance for your time.

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Have you tried using the openPortal portlet-container? The doc says it will install onto weblogic: https://portlet-container.dev.java.net/public/Download.html

Update: I just installed the portlet-container into the weblogic container and successfully deployed one of the sample portlets from this page: \http://portlet-container.dev.java.net/public/Samples.html