I'm unable to reproduce the issue here...
Code:
        RadFlowInput var PortC.4
        ColFlowInput var PortC.5

        ColFlow var word
        RadFlow var word

        pause 500
        hserout ["Testing...",13,10]                

start:        
        pulsin colflowinput,0,colfloW
        pulsin radflowinput,0,radfloW
          

        hserout ["    PORTC.4=",DEC rADFLOW,_
                 "    PORTC.5=",DEC cOLFLOW,13,10]

        GOTO START
Seems to be a hardware problem... if you have any schematic and part#, that would be handy.