Problem in AT+CPBR Command with PIC18F452

[softlab]

Dear all,

I can able to send and receive all AT Commands except (AT+CPBR and AT+CMGR Commands). I want to store all the phone book entries (already stored in SIM) into array. So, When I start the GSM Modem/Module, I issue AT+CPBR=1,250 command and read the Phone Book (SIM) and Store the Phone numbers into the array. If I issue AT+CPBR command, it executes well and return the phone book records and hangs. I don't know why. All other commands work fine. Any help? I give you my code here. Pl go thro' that and pl let me know if you found any errors. The code could be little large. Inconvenience regretted.

/* MAKE RECEIVE AS HIGH INTERRUPT PRIORITY */
#pragma code rx_interrupt = 0x8 //high interrupt vector
void rx_int (void)
{
    if (PIR1bits.RCIF){
        PIR1bits.RCIF = 0; // clear interrupt flag
        rx_handler();
    }
    return;
}
#pragma code

#pragma interrupt rx_handler // changed the interrupt to interruptlow
void rx_handler (void)
{
  unsigned char input;
  
  input = ReadUSART();
    
	switch(input){
            
	case '\x0A': // if line feed detected in the GSM output i.e. '\n'
                        break;
            case '\x0D': // if carriage return detected i.e. '\r'
                        gsmOutput_c[i] = '\x00';
           		lenOfGSMOutput = strlen((char*)gsmOutput_c);
                        if (lenOfGSMOutput > 0){
	                     i = 0;
	   	            lenOfGSMOutput = 0;
                            showGSM_DATA(gsmOutput_c);
                            *gsmOutput_c = 0;
                            
                            PIE1bits.RCIE = 1; // enable receive interrupts
                            
                        }
                        break;
                        			
        default: // if characters received
		if(i < 80){
		           gsmOutput_c[i] = input;
			i++;
		}
		else{
			i = 0;
		}
                break;
        }//end for switch
}

//Processing and Validating GSM_MODEM_OR_MODULE OUTPUT

void showGSM_DATA(char gsmOutput_s[]){
    
    if (strcmppgm2ram(gsmOutput_s, (const far rom char*)"OK") == 0){
       OK = TRUE;
    }
    if (strcmppgm2ram(gsmOutput_s, (const far rom char*)"ERROR") == 0){
       OK = FALSE;
     return;
    }
        	
	if (strcmp(gsmOutput_s, NO_CARRIER) == 0){
		WriteCmdXLCD(CLR_LCD); 
		while(BusyXLCD()); 
		WriteCmdXLCD(HOME_LCD); 
		while(BusyXLCD()); 
		putrsXLCD("NO CARRIER");
     return;
	}
	
	if (strcmp(gsmOutput_s, Error) == 0) {
		WriteCmdXLCD(CLR_LCD); 
		while(BusyXLCD()); 
		WriteCmdXLCD(HOME_LCD); 
		while(BusyXLCD()); 
		putrsXLCD("Error");
     return;
	}
    
    if (strcmppgm2ram(NextGSMCmd, (const far rom char*) "PhBk_Stored") == 0){
        
        *NextGSMCmd = 0;
        *gsmOutput_s = 0;
        
        WriteCmdXLCD(CLR_LCD); 
		while(BusyXLCD()); 
		WriteCmdXLCD(HOME_LCD); 
		while(BusyXLCD());
        
        if (OK == TRUE){
            OK = FALSE;
    		putrsXLCD("PH BK READ - OK");
        }
        else{
            putrsXLCD("PH BOOK ERROR");
        }
     return; 
    }
    
    if (strlen(gsmOutput_s) > 5){
        
	strBuff = 0;
	i = 0;
       
	while(i < 5){
		strBuff[i] = gsmOutput_s[i];
		i++;
	}
	strBuff[i] = '\x00';
	i = 0;
		
	if (strcmppgm2ram(strBuff, (const far rom char*)"+CPBR") == 0){
            
            *strBuff = 0;
            if (strcmppgm2ram(NextGSMCmd, (const far rom char*) "store_PhBk_Into_Array") == 0){
                strcpypgm2ram(NextGSMCmd, (const far rom char*) "PhBk_Stored");

Here the problem araises. If I comment the LCD Commands as follows, it works fine. But If I uncomment, The text "gsmOutput_s" displayed and hangs.

                /*
                *gsmOutput_s = 0;
                WriteCmdXLCD(CLR_LCD); 
            while(BusyXLCD()); 
            WriteCmdXLCD(HOME_LCD); 
            while(BusyXLCD()); 
            putrsXLCD("gsmOutput_s");
               */
            }
          return;
        }
    } 
}

void main (void)
{

    TRISA = 0; // RS, R/W, E pins of LCD
    /* Configure all PORTB pins for output except RB0*/
    TRISB = 0; // RB0 as Input for Interrupt
    TRISD = 0; // set PORTD as Output for LCD (D4 to D7) 
    PORTB = 0; // Initialize portB
    PORTD = 0; // Initialize PORTD
    
    /* Make receive interrupt high priority */
    IPR1bits.RCIP = 1;
    
    /* Enable interrupt priority */
    RCONbits.IPEN = 1;
    /* Enable all high & low priority interrupts */
    INTCONbits.GIEH = 1;  // interrupt on RB0
    
    OpenXLCD(FOUR_BIT & LINE_5X7); // Open and Initialize LCD
	
    /*
    * Open the USART configured as
    * 8N1, 9600 baud, in polled mode
    */
    OpenUSART (USART_TX_INT_OFF &    //Set and Open Serial Port
               USART_RX_INT_ON &
               USART_ASYNCH_MODE &
               USART_EIGHT_BIT &
               USART_CONT_RX &
               USART_BRGH_HIGH, 25);
    
    i = 0;
    
    OK = FALSE;
    strcpypgm2ram(NextGSMCmd, (const far rom char*) "store_PhBk_Into_Array");
    
    while (BusyUSART());
    putrsUSART((const far rom char *)"AT+CPBR=1");
    while (BusyUSART());
    putcUSART(0x0A);
    putcUSART(0x0D);
    
    /* Loop forever */
    while (1);
    // maintain the power-down mode until interrupt occurred 
    // and return to sleep once if the interrupt has been serviced***
    
}