This another minor issue that has effected a few bikes. I think that all of them will see it sooner or later no matter what the year. The plug wire rubs on the sharp edge of the frame it passes over. After time the wire will wear enough to cause shorting, resulting in a rough and choppy running engine.

This one's probably the simplest of the bunch. Just wrap the offending section of wire with black tape, or even better, pick up some wiring loom and make the fix look sano. While you're at it, check the braided vent from the valve cover to the reservoir and the small radiator crossover tube for abrasion. Both of them on my '00 had worn on neighboring clamps.