Lpc2000

Hi 

I'm having problems with the external interrupt 0 using it in a 
falling edge sensitive mode. I have no problems using interrupts 2&3. 
Something in the processor is getting corrupted since the debugger 
crashes out and I have to erase the chip using the serial isp to get 
it back. I can't see what is wrong with the following code -

PINSEL1_bit.P0_16=0x1; 

EXTINT = 0x01;

VPBDIV = 0x0;		

EXTMODE = 0x01;		

VPBDIV = 0x01;				

VPBDIV = 0x01;	
								
						
// enable the interrupt control	
VICIntSelect &= ~(1<<VIC_EINT0); 	
VICVectAddr3 = (uint32_t)&HwInterrupt0Interrupt;	
VICVectCntl3 = 0x20 | VIC_EINT0;for external 0			
VICIntEnable = (1<<VIC_EINT0);