Arfstorm, I see you have your regulator up but for me I'd like to try and find something that isn't body ground (I have a plastic underside to my seat where I screw everything to). So it looks like its back to surfing the site and surfing the web for me
My solution, includes a ground strap. If you noticed one of the pics in my photo album has I have ran a ground strap from a bolt head/screw head, to the negative feed to the harness. which solves all the needs the bike has for grounding the Reg...
The First image shows the screw head/washer attached to the back of the reg. I used that type of washer, to ensure it makes a metal to bolt connection.
The second image shows the black ground strap, it is attached to the ground connector on the harness, just like the original showed. my concern was I didn't know how much resistance their was by allowing the grounding via the metal to aluminum, to the frame, so I did the ground strap.
I had attached this next to the plastic fender, so I was contemplating attaching it to the fender.
second image