Hi All, and apologies for not getting back to you all sooner (damned work!!)
I hate to admit this, but a wire had gotten disconnected on my bread board - amazing how much better a PIC works when it has a five volt supply...
My zero crossing detector works great, and I'm getting a nice clean pulse train to my triac optocoupler. Now to go back to the code to make my kitchen heater controller - I'm making a sous vide controller for a crockpot..
Thanks again for all the help - before I tear hair out again I'll make sure to check my hardware first...
Alec