Hi Jim,

Without knowing what sort of problems you're having, and what processor you're using, there's not much I can say. What I can say is that I've been using AMD processors and VFP for the last three years, and I had NO problems. I would look somewhere else: drivers, memory, or even the motherboard.
If you suspect the equipment, there's a chance that that particular processor may be damaged (caused by heat problems for example).