it would seem to me that stiffening the rear in compression and the front in rebound would keep the headshaking subdued. maybe someone else can confirm that and explain the side effects of making such an adjustment.
I thought speeding up the steering causes insability, such as with steeper rake? If you raise the rear aren't you making the rake more steep/unstable? Make sure the Preload and Sag are set-up properly, makes a huge difference with the 954's.
I also noticed with the manual's recomemded tire pressure the bike was real skidsh, I dropped mine to 32 front, 34 rear, do what makes ya comfy.
Bladerunner, do you have the adjusting shims for the rear ride height or making them?
HP is a poor substitute for experience and ability.
What bike do you ride? Did you buy it new (has someone else had a chance to mess with it)? When is the headshake occuring (track or street)? A lot of factors can conspire to produce headshake, and it's inherent in some bikes more than others due to design. There's no easy answer, but a good place to start, especially if you are not the only person who has owned the bike is to return evrything to factory settings (including fork height in the triple clamps) nad then set the static sag and pre-load. That should get things in the ball park and allow you to make changes slowly and methodically to suit your style of riding. Remember, write adjustments down as you do them so you can easily go back a step or two if you have to.