I had a leak driving me nuts for about 4 months and just figured it out last week. It was clear and oily, but would disapate into the concrete on the garage floor. Turned out to be coolant that leaked out of the 14mm hex plug on the right rear of the engine block, right in front of the triangular shroud. Took me the better part of a day to track down that hex key and about 10 seconds to give it a couple of good wacks to tighten it!
I was under that bike with a mirror forever trying to figure it out and the way it sneeked around to drip where it did really suprised me.
Hope you get it solved.