Magari non � la sezione giusta ma siccome usa Bootstrap (JS+Jquery+CSS) magari � calzante.

Quello che segue � il codice di un accordion Bootstrap che genero via codice server side... il risultato � che mi mostra i panel "padri" tutti correttamente chiusi ma cliccandoli non li apre per mostrarmi i relativi panel figlio, qualcuno sa dirmi cos'ha di sbagliato?
L'inspect col Firebug non mostra nessun errore... eppure...

Grazie!

codice:
<div class="panel">
        <div id="accordion" class="panel-group" role="tablist">
           
        
              <!-- per ogni articolo -->
            <div class="panel panel-default" >
                <div class="panel-heading">
                  <h4 class="panel-title">
                    <a href="#RAT13S001-01" data-parent="#accordion" data-toggle="collapse" class="accordion-toggle collapsed">
                      RAT13S001-01 -  BORSA A.T. xxx 
                    </a>
                  </h4>
                </div>

                <div class="panel-collapse collapse" id="RAT13S001-01" style="height: 0px;">
                    <div class="panel-body">
                    <!-- per ogni variante -->
                     
                        
                              
                                      <table>
                                          <tr>
                                              <td>RAT13S001-01BK</td>
                                              <td>BORSA A.T. xxx BLACK</td>
                                              <td><span id="ContentPlaceHolder1_righe_subrighe_0_lretail_0">0</span></td>
                                              <td><span id="ContentPlaceHolder1_righe_subrighe_0_lprice_0">0</span></td>
                                              <td><input name="ctl00$ContentPlaceHolder1$righe$ctl00$subrighe$ctl00$rqta" type="text" value="0" id="ContentPlaceHolder1_righe_subrighe_0_rqta_0" /></td>
                                              <td><span id="ContentPlaceHolder1_righe_subrighe_0_ltot_0">0</span></td>
                                          </tr>
                                      </table>
                         
                            
                              
                                      <table>
                                          <tr>
                                              <td>RAT13S001-01BR</td>
                                              <td>BORSA A.T. xxx BROWN</td>
                                              <td><span id="ContentPlaceHolder1_righe_subrighe_0_lretail_1">0</span></td>
                                              <td><span id="ContentPlaceHolder1_righe_subrighe_0_lprice_1">0</span></td>
                                              <td><input name="ctl00$ContentPlaceHolder1$righe$ctl00$subrighe$ctl01$rqta" type="text" value="0" id="ContentPlaceHolder1_righe_subrighe_0_rqta_1" /></td>
                                              <td><span id="ContentPlaceHolder1_righe_subrighe_0_ltot_1">0</span></td>
                                          </tr>
                                      </table>
                         
                            
                              
                                      <table>
                                          <tr>
                                              <td>RAT13S001-01FX</td>
                                              <td>BORSA A.T. xxx FUXIA</td>
                                              <td><span id="ContentPlaceHolder1_righe_subrighe_0_lretail_2">0</span></td>
                                              <td><span id="ContentPlaceHolder1_righe_subrighe_0_lprice_2">0</span></td>
                                              <td><input name="ctl00$ContentPlaceHolder1$righe$ctl00$subrighe$ctl02$rqta" type="text" value="0" id="ContentPlaceHolder1_righe_subrighe_0_rqta_2" /></td>
                                              <td><span id="ContentPlaceHolder1_righe_subrighe_0_ltot_2">0</span></td>
                                          </tr>
                                      </table>
                         
                            
                    <!-- fine per ogni variante -->

                    </div>
                </div>
            </div>
            <!-- fine per ogni articolo -->
            
            
              <!-- per ogni articolo -->
              <div class="panel panel-default" >
                <div class="panel-heading">
                  <h4 class="panel-title">
                    <a href="#RAT13S001-02" data-parent="#accordion" data-toggle="collapse" class="accordion-toggle collapsed">
                      RAT13S001-02 - BORSA A.T. xxx 
                    </a>
                  </h4>
                </div>

                <div class="panel-collapse collapse" id="RAT13S001-02" style="height: 0px;">
                    <div class="panel-body">
                    <!-- per ogni variante  -->
                     
                        
                                      <table>
                                          <tr>
                                              <td>RAT13S001-02FX</td>
                                              <td>BORSA A.T. xxx FUXIA</td>
                                              <td><span id="ContentPlaceHolder1_righe_subrighe_1_lretail_2">0</span></td>
                                              <td><span id="ContentPlaceHolder1_righe_subrighe_1_lprice_2">0</span></td>
                                              <td><input name="ctl00$ContentPlaceHolder1$righe$ctl01$subrighe$ctl02$rqta" type="text" value="0" id="ContentPlaceHolder1_righe_subrighe_1_rqta_2" /></td>
                                              <td><span id="ContentPlaceHolder1_righe_subrighe_1_ltot_2">0</span></td>
                                          </tr>
                                      </table>
                         
                            
                              
                                      <table>
                                          <tr>
                                              <td>RAT13S001-02GR</td>
                                              <td>BORSA A.T. xxx GREEN</td>
                                              <td><span id="ContentPlaceHolder1_righe_subrighe_1_lretail_3">0</span></td>
                                              <td><span id="ContentPlaceHolder1_righe_subrighe_1_lprice_3">0</span></td>
                                              <td><input name="ctl00$ContentPlaceHolder1$righe$ctl01$subrighe$ctl03$rqta" type="text" value="0" id="ContentPlaceHolder1_righe_subrighe_1_rqta_3" /></td>
                                              <td><span id="ContentPlaceHolder1_righe_subrighe_1_ltot_3">0</span></td>
                                          </tr>
                                      </table>
                         
                            
                    <!-- fine per ogni variante -->

                    </div>
                </div>
            </div>
            <!-- fine per ogni articolo -->
            
        </div>
</div>