Fast Interrupts

hi all,
I am testing the working of fast interrupts.
I have set the interrupt as CACHED.

what is wrong with the following code?

void main(void)
{
  uwBank_set = 0;

  FINT0CSP   = 0x8F01;
  FINT0ADDR  = 0xFF00;
  GPT1_vStartTmr(GPT1_TIMER_3);
  while(!uwBank_set);
  GPT1_vStopTmr(GPT1_TIMER_3);
}