[PIC] debugger haults unexpectedly

volatile uint_8 TransferRateComplete=0;
extern usint_16 PeriodValue,TransferRateCount;

void __ISR(4,ipl7)TIMER1_handlar(void)
{
	if(IFS0bits.T1IF)
	{
		IFS0bits.T1IF = 0;      //clear flag.
		PR1 = 19531;		//1 sec value.
		TransferRateCount++;
		
		if(TransferRateCount ==( PeriodValue))
		{			
			TransferRateCount = 0;
			TransferRateComplete = 1;
//			T1CONbits.ON = 0;			//disable timer1
//			PR1 = 0;				//1 sec value.
//			TMR1 = 0;
			
//			SendPacket(PacketData ,PacketDataIndx);
			//MinuteFlag = 1;
//			PR1 = 0x9C40;				//1 sec value.
//			T1CONbits.ON = 1;			//enable timer1			
		}
	}		
	
}

void __ISR(7,ipl7)WATER_LEVEL_INT1_HANDLER(void)
{
    if(IFS0bits.INT1IF)
	{
        if(level=='1')
        {
            level='0';
            
        }
        else
        {
            level='1';
        }
        
         INTCONbits.INT1EP=~INTCONbits.INT1EP;
       // WriteString("SWITCH INTERUPT\n");
         ADC_read();
      
        // WriteString("ADC READ\n");
        calculations();
       //  WriteString("calculations\n");

        set_packet();
        
        // WriteString("packet set \n");
        send_packet();
        
        OpenUart2();
        
       
//		IEC0SET = 0x00000010;			//Enable Timer1 interrupt  
//		T1CONSET = 0x00008000;			//Enable Timer1. 
		IFS0CLR= 0x00000100;	
	}
    
    
    
}