Erro JPA no Windows XP

<?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" version="1.0" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
    <persistence-unit name="pu1">
        <provider>oracle.toplink.essentials.ejb.cmp3.EntityManagerFactoryProvider</provider>
        <class>generico.model.Estado</class>
        <properties>
            <property name="toplink.jdbc.driver" value="org.postgresql.Driver"/>
            <property name="toplink.jdbc.url" value="jdb:postgresql://200.129.157.201:5432/generico"/>
            <property name="toplink.jdbc.user" value="postgres"/>
            <property name="toplink.jdbc.password" value="654321"/>
            <property name="toplink.logging.level" value="INFO"/>
        </properties>
    </persistence-unit>
</persistence>

package generico.model;

import java.util.List;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.OneToMany;

@Entity
public class Estado
{
	@Id
	@Column (insertable = false)
	@GeneratedValue (strategy = GenerationType.SEQUENCE, generator = "estado_id_seq")	
	private int id;
	private String sigla;
	private String nome;
	@OneToMany
	private List<Cidade> cidades;
	
	public Estado()
	{
		
	}	
        ....
}

package generico.persistence;

import java.util.List;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;

public class BaseDao<T> 
{  
  private static EntityManagerFactory emf;
  private EntityManager em;

  public BaseDao() 
  {
    emf = Persistence.createEntityManagerFactory("pu1");
    em = emf.createEntityManager();
  }

  public boolean create(T obj)
  {
    em.getTransaction().begin();
    try 
    {
      em.persist(obj);
      em.getTransaction().commit();
      return true;
    }
    catch (Exception e) 
    {
      e.printStackTrace();
      em.getTransaction().rollback();
      return false;
    }
  }

public class ClientEstado 
{
	public static void main(String[] args)
	{		
		Estado estado = new Estado();
                //Atribui valores a estado
               ...

               //Persistência usando o JPA
		BaseDao<Estado> estadoDao = new BaseDao<Estado>();
		estadoDao.create(estado);
         }
}