I have an ADI pilot II which after about two hours started having pitch oscillation problems. These tended to be random, but the autpilot tried to stay at the requested altitude. We have adjusted the settings on the autopilot as suggested by Trutrak. We have tried the static lag setting increase. We have disconnected the static lines from the autopilot to see if that was the issue. Trutrak gave us a replacement unit, even though they could find nothing wrong with the first unit. The second unit did the same thing on the 3rd flight after a few hours on the unit. Any suggestions? There is no excess play in the elevator when compared to other RV's on the field.