Почему советник зависает?

Здравствуйте! Я пробую написать советник,который подсчитывает количество ордеров каждого вида.При выполнении с функцией  OrderSelect, он почему-то всегда зависает,но когда она закоментированна,все работает. Я работал с функцией  OrderSelect и раньше, и таких проблем не возникало, но этот случай вообще не пробиваемый для меня!Помогите пожалуйста!!!

//+------------------------------------------------------------------+
//|                                                         test.mq4 |
//|                        Copyright 2012, MetaQuotes Software Corp. |
//|                                        https://www.metaquotes.net |
//+------------------------------------------------------------------+
#property copyright "Copyright 2012, MetaQuotes Software Corp."
#property link      "https://www.metaquotes.net"

//+------------------------------------------------------------------+
//| expert initialization function                                   |
//+------------------------------------------------------------------+
int OrdTotl;  // Всего ордеров
int OrdType;  // Тип ордера
//int sum;      // Сумма всех ордеров

int CountBUY;       // 0
int CountSELL;      // 1
int CountBUYLIMIT;  // 2
int CountSELLLIMIT; // 3
int CountBUYSTOP;   // 4
int CountSELLSTOP;  // 5



int init()
  {
//----
   OrdTotl        = 0;
   
   CountBUY       = 0;
   CountSELL      = 0; 
   CountBUYLIMIT  = 0; 
   CountSELLLIMIT = 0;
   CountBUYSTOP   = 0;  
   CountSELLSTOP  = 0; 
//----
   return(0);
  }
//+------------------------------------------------------------------+
//| expert deinitialization function                                 |
//+------------------------------------------------------------------+

  
/////////////////////////////////////////////////////
//// OrdersCounter //////////////////////////////////
/////////////////////////////////////////////////////
void OrdersCounter()  // Счетчик ордеров
{
 int sum = OrdersTotal();
 
  while(sum != 0 )
   {
    OrderSelect(sum-1,SELECT_BY_POS);
    RefreshRates();
    OrdType = OrderType();
       
    switch(OrdType)
    {        
     case 0: 
     CountBUY++;
     break;
          case 1:
          CountSELL++;
          break;
                case 2:
                CountBUYLIMIT++;
                break;
                      case 3:
                      CountSELLLIMIT++;
                      break;
                            case 4:
                            CountBUYSTOP++;
                            break;
                                  case 5:
                                  CountSELLSTOP++;
                                  break;
    default:
    Comment("\n\n                                                   No orders" );
    }
  } 
}

/////////////////////////////////////////////////////
//// OrdersShow /////////////////////////////////////
/////////////////////////////////////////////////////

void OrdersShow()
{
 
 OrdersCounter();
 Comment("\n\n\n                                                   OrdersTotal = ",OrdersTotal(),
         "\n                                                   BUY = ",CountBUY,
         "\n                                                   SELL = ",CountSELL,
         "\n                                                   BUY LIMIT = ",CountBUYLIMIT,
         "\n                                                   SELL LIMIT = ",CountSELLLIMIT,
         "\n                                                   BUY STOP = ",CountBUYSTOP,
         "\n                                                   SELL STOP = ",CountSELLSTOP
        );
}


/////////////////////////////////////////////////////
//// Orders /////////////////////////////////////////
/////////////////////////////////////////////////////  
void Orders()
{
 
 
 
  



} 
 
//+------------------------------------------------------------------+
//| expert start function                                            |
//+------------------------------------------------------------------+
int start()
  {
//----
  
  OrdersShow();
//----
   return(0);
  }
//+------------------------------------------------------------------+