Mapowanie ManyToMany

Witam , chce przeprowadzić takie mapowanie klasy User z PCStation

package com.hibernate.user;

import java.util.Set;

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.Table;

@Entity
@Table(name = "Stationes")
public class PCStation
{
	private int id;
	private String desc;
	private Set<User> users;
	
	public PCStation(){}
	
	
	@Id
	@GeneratedValue(strategy=GenerationType.IDENTITY)
	@Column(name = "station_id",unique = true,nullable=false)
	public int getId() 
	{
		return id;
	}
	
	public void setId(int id) 
	{
		this.id = id;
	}
	
	@Column(name = "opis",unique=false,nullable=true,length=100)
	public String getDesc()
	{
		return desc;
	}
	
	public void setDesc(String desc)
	{
		this.desc = desc;
	}
	
	@ManyToMany(cascade=CascadeType.ALL)
	@JoinTable(name ="Users_Stationes",joinColumns = {@JoinColumn(referencedColumnName="station_id")}
										,inverseJoinColumns={@JoinColumn(referencedColumnName="user_id")})	
	public Set<User> getUsers()
	{
		return users;
	}
	
	public void setUsers(Set<User> users) {
		this.users = users;
	}
		
}

package com.hibernate.user;

import java.util.Set;

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.ManyToMany;
import javax.persistence.OneToMany;
import javax.persistence.OneToOne;
import javax.persistence.Table;


@Entity
@Table(name = "user")
public class User 
{	
	private int id;
	private String name;
	private String surname;
	private UserInfo info;
	private Set<Phone> phones;
	private Set<PCStation> stationes;
	
	public User() {}
	
	
	@Id
	@GeneratedValue(strategy = GenerationType.IDENTITY)
	@Column(name = "user_id", unique = true, nullable = false)
	public int getId() 
	{
		return id;
	}

	public void setId(int id)
	{
		this.id = id;
	}

	@Column(name = "name", nullable = false)
	public String getName()
	{
		return name;
	}

	public void setName(String name) 
	{
		this.name = name;
	}
	
	@Column(name = "surname", nullable = false)
	public String getSurname() 
	{
		return surname;
	}

	public void setSurname(String surname)
	{
		this.surname = surname;
	}
	
	@Override
	public String toString()
	{
		return "[ID: "+id+" NAME: "+name+" SURNAME: "+surname+"]";
	}
	
	@OneToMany(cascade=CascadeType.ALL,mappedBy = "user")	
	public Set<Phone> getPhones() 
	{
		return phones;
	}


	public void setPhones(Set<Phone> phones) 
	{
		this.phones = phones;
	}
	
	@OneToOne(cascade=CascadeType.ALL,mappedBy="user")	
	public UserInfo getInfo()
	{
		return info;
	}


	public void setInfo(UserInfo info) 
	{
		this.info = info;
	}


	@ManyToMany(mappedBy="users")
	public Set<PCStation> getStationes() 
	{
		return stationes;
	}


	public void setStationes(Set<PCStation> stationes)
	{
		this.stationes = stationes;
	}
	
	
}

public static void main(String[] args)
	{		
		
		Configuration configuration = new Configuration().configure(HibernateClient.class
				.getResource("hibernate.cfg.xml"));
		StandardServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().applySettings(
				configuration.getProperties()).build();
		SessionFactory sessionFactory = configuration.buildSessionFactory(serviceRegistry);
		
		Session session = null;
		Transaction transaction = null;
		
		try
		{
			
			session = sessionFactory.openSession();
			transaction = session.beginTransaction();
			
			
			User user = new User();
			user.setName("Pete");
			user.setSurname("Piotrowski");
			
			User user2 = new User();
			user.setName("David");
			user.setSurname("Davidson");
			
			Set<User> users = new HashSet<User>();
			users.add(user);
			users.add(user2);
			
			PCStation s1 = new PCStation();
			s1.setDesc("Nr.1");
			
			PCStation s2 = new PCStation();
			s2.setDesc("Nr.2");
			
			s1.setUsers(users);
			s2.setUsers(users);			
			
			session.save(s1);
			session.save(s2);			
			
			transaction.commit();
		}
		catch(Exception ex)
		{
			transaction.rollback();
		}
		finally
		{
			sessionFactory.close();
		}

Hibernate generuje odpowienie tabele jednak nie zapisuje do nich danych. Co może być tego przyczyną?

@Update, Oki znalazłem już błąd. Zmęczenie, wieczór dają znać o sobie niestety.

@Update2
Otóż problem polegał tylko i wyłącznie na literówce, dodawałem do kolumny nullable=false wartość pusta poprzez literówkę w zmiennej;)