Watch Dog Timer

[Widgetman]

Hi All,
I ran into a interesting issue playing around wih the interrupts on a 18F67J60, and was wondering if there is a trick to using the WDT module. When I added in the line of code below to a compiling file it barks at me that the WDT is not defined. I wanted to tickle the wdt in my ISRRX routine once in a while to see if the ISRRX is crawling off in a hole somehow. I have another interrupt blinking a LED once a second and it still works yet after a few days I can not communicate with my device any more. Any ideas what would cause a compiler error like this ??
Thanks

error system.bas(104) Identifier not declared: WDT

I have the added the two lines below in my clode

#option WDT = true
Include "wdt.bas"