I had a similar leak on my 04 RK. It would drip from the bottom of the bike, roughly in line with the drain plug. It didn't look like it was leaking from the plug, more like it was coming from somewhere 'up and underneath' the bike. Mine turned out to be, I'd forgotten to torque the drain plug after changing the primary fluid. I'd put it back in, finger-tight, but forgot to wrench it. (Doesn't take much torque, think it's inch-pounds scale). It wouldn't leak, sitting. But after I rode any distance, out it would come. More of a 'sheen' of lube, rather than a run, or a drip. The wind must have smoothed and flattened it out, and blew it onto the bottom of the bike, where it collected. After a 30 or 40 minute ride, I'd get a few drops under the bike on the ground/floor after I'd stop (and after having wiped everything off under there real good before hand). The Formula+ didn't appear to be coming from the plug. But it sure was.
If you haven't already, I suggest you inspect the o-ring seal, replace if it's not perfect, and make sure the drain plug is torqued to spec, and go from there.
Alan
Last edited by AlanStansbery; Oct 1, 2011 at 10:31 AM.