when I first started out, I had a heck of a time using it to, but I'm to
cheap to buy a c compiler, so I only know the assembly.  One thing that
took me forever to figure out is that you must clear the watch dog timer
even if it is disabled to get it to work. Some other things...do you have
the intcon bit #5 and #7 set? did you clear the timer (or load it with any
value)? that last action is what really starts it.  after all that it done
you should get an interupt on overflow from 0xff to 0x00.  First of all, I
hope I'm right, because I'm fairly new to this, second of all, I hope it
helps.

Jonathan Newport