Two things:

1. Sand in some leading edge twist - your leading edge tips should be at least 1/4 inch lower than the nose (this prevents the tips from stalling first).

2. Check your CG - I use the Palos CG calcluator here - http://www.palosrc.com/instructors/cg.htm
Set your CG up for 18%

Report back to us and let us know how these help.

CrazyHerb