If you go to http://www.tige.com/2006/
Then click on the "TIGE Difference"
Then click on "convex / Taps 2"
Then click on "Push the button"
This should help with your adjustment, On our boat once Taps reaches the 4-6 range boat will porpose bad at speeds above 30 mph.
I don't have a problem if we stay at wakeboard speed 18 mph - 25 mph no matter where taps is located.
Hope this helps,