Is there any way you can take a picture of how you are trying to balance and post it here. Something just doesn't add up. The laws of physics don't change. If you add weight to the tail the tail can't go up, or vice versa. Something isn't right. A picture would go a long way to figure this out.

I have the Great Planes CG machine as well and it's a good tool for balancing planes with. I use it balance all of my planes and it does a good job.

Ken