PWM not working?

[Russ Kincaid]

This program runs (produces pulses of varying width):

REM DEVICE = 12F675
    CMCON = 7           'SETS DIGITAL MODE
    ANSEL = 0           'GPIO.0 TO GPIO.3 SET AS DIGITAL
    TRISIO = 0          'ALL OUTPUTS BUTGP3 (PIN4) IS INPUT ONLY
    VRCON.7 = 0         'TURN OFF VOLTAGE REFERENCE TO SAVE POWER
    DEFINE OSCCAL_1K 1  'TO SAVE OSCILLATOR CALIBRATION
        tme var word    'BEGINNING NUMBER OF PULSE CYCLES(COUNT DOWN)
        d var byte  'DUTY CYCLE OF PULSE, 127=50%
        j var word  'NUMBER OF CYCLES OF PULSE
    START:
       
         FOR d = 50 TO 250
         PWM GPIO.0,d,1
         PAUSEUS 500
         NEXT D
        
       GOTO START 
        end

This program does not:

REM DEVICE = 12F675
    CMCON = 7           'SETS DIGITAL MODE
    ANSEL = 0           'GPIO.0 TO GPIO.3 SET AS DIGITAL
    TRISIO = 0          'ALL OUTPUTS BUTGP3 (PIN4) IS INPUT ONLY
    VRCON.7 = 0         'TURN OFF VOLTAGE REFERENCE TO SAVE POWER
    DEFINE OSCCAL_1K 1  'TO SAVE OSCILLATOR CALIBRATION
        tme var word    'BEGINNING NUMBER OF PULSE CYCLES(COUNT DOWN)
        d var byte  'DUTY CYCLE OF PULSE, 127=50%
        j var word  'NUMBER OF CYCLES OF PULSE
    START:
       
         FOR d = 250 TO 50
         PWM GPIO.0,d,1
         PAUSEUS 500
         NEXT D
        
       GOTO START 
        end

Can anyone explain why this does not run (produces no pulses).