Jonathan got the point of my questions exactly right. The driver ground and the PIC ground should be kept separate.

That power board is fine for a PIC assuming you have nothing else loading it; it's good for 700mA and has the required decoupling. Do you have any decoupling capacitor (100nF typically) on the PIC power pins? Shouldn't really be necessary on a breadboard that size (I'm assuming the PIC is on the breadboard) but sometimes not having one can cause oddities.

Otherwise I can't obviously see where you're going wrong.