EclipseLink can't find my Entity "IllegalArgumentException" - gwt

Question

I'm trying to do a simple persistence test using:
IntelliJ IDEA,
Maven,
Google Guice,
GWT,
EclipseLink and JPA 2.0.
My persistence.xml:
<persistence-unit name="guiceTest" transaction-type="RESOURCE_LOCAL">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<class>utfpr.edu.br.server.model.Contato</class>
<properties>
<property name="javax.persistence.jdbc.url"
value="jdbc:postgresql://127.0.0.1:5432/gwt"/>
<property name="javax.persistence.jdbc.password" value="postgres"/>
<property name="javax.persistence.jdbc.driver" value="org.postgresql.Driver"/>
<property name="javax.persistence.jdbc.user" value="postgres"/>
<property name="eclipselink.ddl-generation" value="create-tables"/>
<property name="eclipselink.logging.level" value="INFO"/>
</properties>
</persistence-unit>
The exception:
[EL Warning]: 2012-06-21 10:18:32.846--The collection of metamodel types is empty. Model classes may not have been found during entity search for Java SE and some Java EE container managed persistence units. Please verify that your entity classes are referenced in persistence.xml using either <class> elements or a global <exclude-unlisted-classes>false</exclude-unlisted-classes> element
java.lang.IllegalArgumentException: Object: Contato{dataNascimento=Thu Jun 21 10:18:31 BRT 2012, id=null, nome='abcd', sobrenome='adsada', numero='12313123', email='lololol#gmail.com'} is not a known entity type.
The test class:
Injector i = PersistenceTestModule.getInjector();
private ContatoDao dao = i.getInstance(ContatoDao.class);
#Test
public void testSave() throws Exception {
Contato cont = new Contato("abcd","adsada","12313123","lollollo#gmail.com",new Date());
dao.save(cont);
assertNotNull(cont.getId());
}
My persistence.xml is corrected placed in resources/META-INF.
I read that is a eclipselink bug here: https://bugs.eclipse.org/bugs/show_bug.cgi?id=338837
They said:
Solution:
There are two ways into this problem.
1) We specify no entities at all and also do not specify
false
- the result of this is a completely empty metamodel
2) We specify only part of the entities via properties
- the result of this is selective IllegalArgumentException errors thrown when
we attempt to use the missing EntityType classes - likely in a Criteria API
query".
I already tried this two solutions but I still got this error.
Please someone help me!