Boost Control again

[stainless1]

Looking at my logs I see Boost varying from 213-235Kpa on an aim boost of 224.... it is a very consistant sine wave. So I guess my other parameters are driving boost control to be over controlled. Proportional, integral and derivitive gain are all set to 2.0... why, because the help example described 2.0. The peaks are about .57 seconds apart, so about 1.75Hz sine wave. This is steady wide open throttle, rising rpm in top gear.
Anybody have a suggestion what might flatten that our a little
Thanks for all help of suggestions.