Lpc2000

I am trying to use P0.3 as a GPIO, but it doesn't seem to be working.
 I define the bit as:
#define ADC_CS  (1 << 3)
but it doesn't work.  If I change it to:
#define ADC_CS  (1 << 19)
I can toggle it just fine using the exact same code.  P0.2 does not
work either.

I am not using the I2C, but I am using SPI.  I am using Timer0;
however, I am not using the Match.

I have even tried forcing the pin to be GPIO using:
PINSEL0 = PINSEL0 & 0xFFFFFF0F;
but that doesn't work either.

Any suggestions?  (Besides swapping in P0.19 for P0.3.)
Matt