problem with input capture in dsPIC30F3011

unsigned int rotateCount=0;
unsigned int timePeriod= 0; current_value=0,previous_value=0;		

void InitIC(void)
{
	IC7CONbits.ICM=3;      // Capture every rising edge
	IC7CONbits.ICBNE=0;  // Input capture buffer is empty
	IC7CONbits.ICOV=0;    // No input capture overflow occured
	IC7CONbits.ICI=0;       // Interrupt on every capture event 
	IC7CONbits.ICTMR=1;  // TMR2 contents are captured on captured event
	IC7CONbits.ICSIDL=0; // Input capture module will continue to operate in CPU Idle mode
	
	IFS1bits.IC7IF = 0;      // Interrupt bit is cleared
	IPC4bits.IC7IP = 3;	  // Set Interrupt priority to 3
	IEC1bits.IC7IE = 1;     // Set the IC7 interrupt enable bit
}

void TMR2_setup(void)
{
	TMR2 = 0x00;			// Clear contents of the timer register 	
	T2CONbits.TCS=1;        	// Timer uses the internal clock when TCS = 0. Using Internal Clock (Fosc/4)
	T2CONbits.T32=0;        	// TMRx and TMRy form a 16-bit timer
	T2CONbits.TCKPS=0;      	// Using 1:1 prescale value 
	T2CONbits.TGATE=0;      	// Timer Gate Accumulation Disabled 
	T2CONbits.TSIDL=0;      	// Continue in Idle Mode 
	T2CONbits.TON=1;        	// Start Timer1 with prescaler settings at 1:1 and 
						// clock source set to the internal instruction cycle
	PR2 = 0xFFFF; 			//Load the Period register with the value 0xFFFF 
	return;
}

void __attribute__((interrupt, no_auto_psv)) _IC7Interrupt (void)
{
	rotateCount=rotateCount + 1;

	if (rotateCount==6)
	{
		previous_value=current_value; 
		current_value=IC7BUF; 
		if(current_value>previous_value) 
		{ 
			timePeriod = current_value-previous_value; 
		} 
		else 
		{ 
			timePeriod = (PR2 - previous_value) + current_value;
 		} 
	
		SendData(timePeriod);   // sending the time period to the host PC
		rotateCount=0;
	}
	IFS1bits.IC7IF = 0;       		//Interrupt bit is cleared
}

int main(void)
  {
  InitIC();
  TMR2_setup();

  for(;;){
     ;
     }
  }