MCH 2.7t

In the following logs and dyno graph you'll see a drop in boost and coresponding drop in power around 3,500 rpm. There is no throttle cut and based on pressure testing, I don't have any boost leaks. I have software from 2 different reputable companies - logs of both show the same drop in boost. The car is set up with standard 3- equipment.

Any thoughts on what the problem is?

<img src="http://pictureposter.audiworld.com/68483/boost_11_7_06.jpg">

<img src="http://pictureposter.audiworld.com/68483/boost_duty_cycle_11_7_06.jpg">

<img src="http://pictureposter.audiworld.com/68483/a6_2001_tip_giac_3-_dyno_09_06_v2.jpg">