com.impetus.kundera.metadata.KunderaMetadataManager - No Entity metadata found for the class

Question

I'm trying to uses queries in my Cassandra DB with Kundera (Cassandra ORM), this queries work in an others project but when I try to do it in webapp (using tomcat 6.0), I got this error :

com.impetus.kundera.metadata.KunderaMetadataManager  - No Entity metadata found for the class

=> JavaNullPointerException.

But when I leave the persistence.xml from my project I got an other error. (NoPersistence.xml found or something ... )

So, my project found Persistence.xml, but not my Entity class : fileCassandra.

You can see my persistence.xml :

   <?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
    http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
    version="2.0">
    <!--  192.168.3.107 -->
    <persistence-unit name="cassandra_pu">
        <provider>com.impetus.kundera.KunderaPersistence</provider>     
        <class>net.***.common.db.***.FileCassandra</class>

        <properties>            
            <property name="kundera.nodes" value="localhost"/>
            <property name="kundera.port" value="9160"/>
            <property name="kundera.keyspace" value="KunderaExamples"/>
            <property name="kundera.dialect" value="cassandra"/>
            <property name="kundera.client.lookup.class" value="com.impetus.client.cassandra.pelops.PelopsClientFactory" />
            <property name="kundera.cache.provider.class" value="com.impetus.kundera.cache.ehcache.EhCacheProvider"/>
            <!-- <property name="kundera.cache.config.resource" value="/ehcache-test.xml"/>    -->           
        </properties>
       </persistence-unit>
</persistence>  

net..common.db..FileCassandra I must replace by * because it's name from my companie ;)