Trouble with JPA

Question

I have this model with 2 tables, "Cuenta" and "Movimien". When the merge () method of the Movimien table is called, it also attempts to insert into the Cuenta table. I am not sure if relationships are right. Could someone give me a hand with this?

Below, the model of the Movimien table, which when doing the update triggers the insert in the Cuenta table:

@Entity
@Table(name = "movimien")
public class Movimien implements Serializable {    

private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private int id;
private Date fecha;
private short cuentaid;
private float importe;
private String concepto;

@JoinColumn(name = "cuentaid", insertable = false, updatable = false)
@ManyToOne
private Cuenta cuenta;

public Movimien() {
   this.cuenta = new Cuenta();
}

public int getId() {
   return id;
}

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

public Date getFecha() {
   return fecha;
}

public void setFecha(Date fecha) {
   this.fecha = fecha;
}

public short getCuentaid() {
   return cuentaid;
}

public void setCuentaid(short cuentaid) {
   this.cuentaid = cuentaid;
}

public float getImporte() {
   return importe;
}

public void setImporte(float importe) {
   this.importe = importe;
}

public String getConcepto() {
   return concepto;
}

public void setConcepto(String concepto) {
   this.concepto = concepto;
}

public Cuenta getCuenta() {
   return cuenta;
}

public void setCuenta(Cuenta cuenta) {
   this.cuenta = cuenta;
}

@Override
public int hashCode() {
   int hash = 7;
   hash = 53 * hash + this.id;
   return hash;
}

@Override
public boolean equals(Object obj) {
   if (this == obj) {
       return true;
   }
   if (obj == null) {
      return false;
   }
   if (getClass() != obj.getClass()) {
      return false;
   }
  final Movimien other = (Movimien) obj;
  if (this.id != other.id) {
      return false;
   }
   return true;
}}

And the model of the Cuenta table, to which the insert is triggered when an update is made in the Movimien table:

@Entity
@Table(name = "cuentas")
public class Cuenta implements Serializable {

  private static final long serialVersionUID = 1L;

  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  private int id;
  private String nombre;
  private short tipo;

  @OneToMany(mappedBy="cuenta")  
  private List<Movimien> movimien;

  public Cuenta() {
     this.nombre="";
     this.tipo = 0;
  }

  public int getId() {
     return id;
  }

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

  public String getNombre() {
     return nombre;
  }

  public void setNombre(String nombre) {
    this.nombre = nombre;
  }

  public short getTipo() {
     return tipo;
  }

  public void setTipo(short tipo) {
    this.tipo = tipo;
  }

  @Override
  public int hashCode() {
     int hash = 7;
     hash = 97 * hash + this.id;
     return hash;
  }

  @Override
  public boolean equals(Object obj) {
     if (this == obj) {
        return true;
     }
     if (obj == null) {
       return false;
     }
     if (getClass() != obj.getClass()) {
       return false;
     }

    final Cuenta other = (Cuenta) obj;

    if (this.id != other.id) {
       return false;
    }
   return true;
}}

Any idea what may be the reason for this behavior?, thanks in advance! Fernando

Persitence.xml

Database

Log of update and insert