Не работает постраничная навигация при выборке из ИБ

<?
               CModule::IncludeModule('iblock');
               $arSelect = Array("ID", "NAME", "DATE_ACTIVE_FROM","PREVIEW_PICTURE");
               $arFilter = Array("IBLOCK_ID"=>1, "ACTIVE"=>"Y", "SECTION_CODE"=>$USER->GetLogin());
               $res = CIBlockElement::GetList(Array("DATE_CREATE"=>"DESC"), $arFilter, false, Array("nPageSize"=>12), $arSelect);

               $res->NavStart(12,false);
               echo $res->NavPrint("Cтр.");
               if($res->SelectedRowsCount()):
               $i=0;
               ?>
                  <table cellspacing="20" cellpadding="0">
                  <tr>
                  <?
                  while($ob = $res->GetNextElement())
                  {
                     $i++;
                     if(($i-1)%3==0 && $i!=1)
                        echo "</tr><tr>";
                     $arFields = $ob->GetFields();
                     $pp=CFile::GetPath($arFields["PREVIEW_PICTURE"]);
                     echo "<td width='33%' align='center' valign='middle'><img id='img_".$arFields['ID']."' src='".$pp."'/></td>";
                  }
                  ?>
                  </table>