Why not put it in one check and save a cycle?

Like this (untested):

Code:
Main:
       Pulsin Porta.0, 1, Width                                          'Wait for a high pulse store the pulse width in the variable "Width."
           if (Width >= 925 ) and ( Width <= 975) then          '1900µs is on state. 1900µs /2 = 950
              high porta.1
           else 
               if (Width >= 475 ) and ( Width <= 525) then           '1000µs is off state. 1000µs /2 = 500  
              low porta.1                                                    'If channel 3 is indeed in the off state turn the LED off. 
           endif
           endif
       goto Main
Ioannis