I'm not there to see your setup, but how about straps from the lower or upper triple clamps down to the lift (if it's a platform lift), like I do here with my homemade setup. I use a wheel chock on a plywood platform, straps down to eye bolts at the front corners of the lift for stability, with my jack stand lifting from the rear of the frame where a centerstand would be mounted.
If you are using some sort of scissor jack lift under the frame, maybe something like what I built might help you.
http://wildguzzi.com/forum/index.php?topic=82965.0Sounds like your bike is rear-heavy. Do you have luggage you could remove to help the center of gravity move forward?
There have been lots of stock motorcycles that tip to the rear wheel while on their centerstands. BMW models, for example.
Steve.