Hi gwelo,
I am not very familiar with the A109E, but was wondering if they use fibre optic gyro's or the mechanical type?
Sometimes the mechanical type can cause this phenomenon in different types of helo's. Just thinking outside the box...or maybe in this case inside the box
Another is depending on operating environment-I had many experiences where helo's with elastomeric bearings on MR head assy's in very cold environments would affect vibration and seem rough after first start of the day and even after take off but within minutes the elastomerics would soften up and helo become smooth again...even if elastomerics were new.
Best of luck
SS