I think what you have there my friend is a leaking gas tank. Is the buildup more dirt than oil? Do you get a stong gas smell when its locked in the garage on a warm day (you should be out riding though)? I bet its on the left side of the tank (from being on the side stand) just above the wiring harness.
I thought I had the same issue when I bought mine... There was an oily/ dirty mess under the gas tank, just near the pivot hinge. I cleaned it off with degreaser; thats when I noticed the gas smell more.
The '00's and '01's have had a few issues with this, and there have been claims hounoured by Honda for some owners in the US, you just have to look through all the forums. Unfortuantly for me, no dealer has heard of this in Australia, so I ended up dremmelling off the paint around the hinge ind filling it in with JB weld. Its been like this for about two years now, and so far so good. Check the harness under the tank as well, as the fuel tends to weaken the tape and rubber around the wires.