StoneColdFuzzy,

Could you post all your code up to your main routine? If we could see what intializations you've done, we might be able to better help. I assume you've set your TRISD register for pin 4 as an output. That leaves comparator pins, which Fredrick addressed, and possibly analog pins - sorry, I don't have the datasheet right in front of me. I'll also make the assumption that you've doubled-checked your wiring. That cost me a mistake for the longest time this week as Darrel can atest to.