Sorry Ralph I wasn't continuing to read this thread as I'd assumed it had already been adequately answered some days ago...

Yes, zero cross is the way to go with inductive loads, plus VDR's (capable of absorbing any transients) across the switching element.

Ensure inductive surges will not penetrate your PSU and it is clean. You've sprinked 100nF Capacitors around your power rails like confetti.

Basic filtering on any other input pins (you'll be surprised what a 10K Resistor and a 100nF Capacitor will stop!).

Site the PIC well away from your switching elements or ensure it is screened and if nescessary has a large ground plane all around and underneath it.

I've not experienced the PIC problems that a lot of folks seem to have, perhaps it's because I build-in all the above recommendations into my PIC designs from the very beginning. It is important to identify what kind of interference is causing your problem... without knowing that you're stabbing in the dark as to a solution. It's overly simplistic saying it's "an inductive load switching". well what's it doing? Is the transient going down the power lines and affecting your PSU? Is it being induced into PCB tracks and coming down other input pins (or being induced locally into the PSU)? Or is it a localised EMP screwing the chip directly. You MUST first identify the root cause before applying a solution otherwise you will just end up wasting hours of your life.