PHP session saving array with POST values

First sorry for my English.

I have a weird problem using the php $_SESSION Object. I spent 2 days without find the solution. I am triying to save a multidimensional array that stores some post values. I create an array with this values and then i create a multidimensional array containing this arrays.

Page 1 (setvalues in multi array ans save in session)-> GET -> Page 2 read the session.

My code Page 1:

First, save the post values into a object property and validate them.

public function validateData(){

        $this->nombres=$_POST["nombre"];
        $this->imp_nombres=$_POST["imp_nombre"];
        $this->numeros=$_POST["numero"];
        $this->imp_numeros=$_POST["imp_numero"];
        $this->tallas=$_POST["talla"];
        $this->cantidades=$_POST["cantidad"];
        $this->productos=$_POST["products"];
        $this->equipos=$_POST["equipo"];


        if(WSI_Funtions::compareSizes($this->nombres,$this->imp_nombres,$this->numeros,$this->imp_numeros,$this->tallas,$this->cantidades,$this->productos,$this->equipos))
        {
            $this->isValidModel=true;
            $this->saveProductsValues();

        }
        else{
          $this->isValidModel=false;
          $this->errorMessage="Los datos no son correctos. Los parametros no coinciden";
        }

}

If data is ok, I save those values:

public function saveProductsValues()
{


    $this->productsValues=array();
    $this->productsValues["names"]=$this->nombres;
    $this->productsValues["imp_nombres"]=$this->imp_nombres;
    $this->productsValues["numeros"]=$this->numeros;
    $this->productsValues["imp_numeros"]=$this->imp_numeros;
    $this->productsValues["tallas"]=$this->tallas;
    $this->productsValues["cantidades"]=$this->cantidades;
    $this->productsValues["productos"]=$this->productos;
    $this->productsValues["equipos"]=$this->equipos;


}

Then I save it in a session :

public function saveSessionValues()
{
    $_SESSION['customer'] = $this->customerObject;
    $_SESSION['productsValues'] =$this->productsValues;
    echo var_dump($_SESSION['productsValues']); 
}

The saveSessionValues echo print this:

array(8) { ["names"]=> array(12) { [0]=> string(0) "" [1]=> string(12) "ÁNGEL HDEZ." [2]=> string(11) "VUJASINOVIC" [3]=> string(4) "ABIA" [4]=> string(10) "MUTAKABBIR" [5]=> string(8) "PETROVIC" [6]=> string(5) "DOBOS" [7]=> string(4) "HOMS" [8]=> string(6) "CASTRO" [9]=> string(0) "" [10]=> string(0) "" [11]=> string(0) "" } ["imp_nombres"]=> array(12) { [0]=> string(0) "" [1]=> string(1) "1" [2]=> string(1) "1" [3]=> string(1) "1" [4]=> string(1) "1" [5]=> string(1) "1" [6]=> string(1) "1" [7]=> string(1) "1" [8]=> string(1) "1" [9]=> string(0) "" [10]=> string(0) "" [11]=> string(0) "" } ["numeros"]=> array(12) { [0]=> string(1) "7" [1]=> string(1) "8" [2]=> string(1) "9" [3]=> string(0) "" [4]=> string(2) "11" [5]=> string(2) "12" [6]=> string(2) "18" [7]=> string(2) "19" [8]=> string(2) "22" [9]=> string(1) "5" [10]=> string(2) "33" [11]=> string(0) "" } ["imp_numeros"]=> array(12) { [0]=> string(1) "1" [1]=> string(1) "1" [2]=> string(1) "1" [3]=> string(0) "" [4]=> string(1) "1" [5]=> string(1) "1" [6]=> string(1) "1" [7]=> string(1) "1" [8]=> string(1) "1" [9]=> string(1) "1" [10]=> string(1) "1" [11]=> string(0) "" } ["tallas"]=> array(12) { [0]=> string(4) "XXXL" [1]=> string(3) "XXL" [2]=> string(2) "XL" [3]=> string(3) "XXL" [4]=> string(3) "XXL" [5]=> string(3) "XXL" [6]=> string(4) "XXXL" [7]=> string(3) "XXL" [8]=> string(2) "XL" [9]=> string(4) "XXXL" [10]=> string(2) "XL" [11]=> string(3) "XXL" } ["cantidades"]=> array(12) { [0]=> string(1) "1" [1]=> string(1) "1" [2]=> string(1) "1" [3]=> string(1) "1" [4]=> string(3) "145" [5]=> string(1) "1" [6]=> string(1) "1" [7]=> string(1) "1" [8]=> string(1) "1" [9]=> string(1) "1" [10]=> string(1) "1" [11]=> string(1) "1" } ["productos"]=> array(12) { [0]=> string(3) "109" [1]=> string(3) "109" [2]=> string(3) "109" [3]=> string(3) "109" [4]=> string(3) "109" [5]=> string(3) "109" [6]=> string(3) "109" [7]=> string(3) "109" [8]=> string(3) "109" [9]=> string(3) "109" [10]=> string(3) "109" [11]=> string(3) "109" } ["equipos"]=> array(12) { [0]=> string(7) "LEB ORO" [1]=> string(7) "LEB ORO" [2]=> string(7) "LEB ORO" [3]=> string(7) "LEB ORO" [4]=> string(7) "LEB ORO" [5]=> string(7) "LEB ORO" [6]=> string(12) "ES TALLA 4XL" [7]=> string(7) "LEB ORO" [8]=> string(7) "LEB ORO" [9]=> string(12) "ES TALLA 4XL" [10]=> string(7) "LEB ORO" [11]=> string(7) "LEB ORO" } }

My code Page 2 (php tags ommitted):

if (!isset($_SESSION)) { session_start(); }
echo var_dump($_SESSION['productsValues']);

This echo print the next value:

array(8) { ["names"]=> NULL ["imp_nombres"]=> NULL ["numeros"]=> NULL ["imp_numeros"]=> NULL ["tallas"]=> NULL ["cantidades"]=> NULL ["productos"]=> NULL ["equipos"]=> NULL }

The first level array exists, because the subarrays keys are printed, but all the second level arrays are NULL..

Maybe is for use the $_POST value?? I had try to encode the values of the $_POST object, saving only a json string instead of saving a object with the same result, the first nodes in the JSON are the keys of the arrays but the values are "NULL"

Any help please?? Thanks!!