Help setting sleep mode

Hello
Here is my sample code:

TRISIO=%011111
GPIO=0
w1 VAR word
by var byte
intcon=%10001000
ioca=%111111
cmcon0=7
Include "modedefs.bas"

ON INTERRUPT GOTO START

START:
if gpio.0=1 then ZERO
IF GPIO.1=1 THEN ONE
IF GPIO.2=1 THEN Two
IF GPIO.4=1 THEN FOUR
INTCON.0=0
SLEEP 60
GOTO START

ZERO:
serout GPIO.5,N2400,["abc",22]
pause 50
LOW GPIO.0
goto start
ONE:
serout GPIO.5,N2400,["abc",66]
pause 50
LOW GPIO.1
goto start
Two:
serout GPIO.5,N2400,["abc",88]
pause 50
LOW GPIO.2
goto start
FOUR:
serout GPIO.5,N2400,["abc",44]
pause 50
LOW GPIO.4
goto start
What I would like to achieve with my 12F635 is that it should stay in sleep mode untill any of the gpio 0,1,2,4 is pressed.
The config register reads as follows (I have made changes to 12f635.inc in PBP folder):
__config _INTRC_OSC_NOCLKOUT & _PWRTE_OFF & _WDT_ON &

_MCLRE_OFF & _CP_ON & _WUREN_ON & _CPD_ON & _IESO_OFF

Could someone let me know what am I doing wrong as my PIC is not responding to pins high.