Autopilot Problem FS2004 KingAir 350

I have a problem with my sim. When I engage the AP the aircraft aggressively pitches over even though the ALT is set at an altitude above the current altitude and the VS is set at a positive rate. Only happens in the KA350 model not, say, in a 172. I have Goflight Module as the AP control and FSUIPC (registered) with the AP mode buttons interfaced to hardware pushbuttons.

Once I disengage the AP during the pitch over and reengage the AP, the aircraft will pitch correctly and capture the altitude. Oh, when it first pitches over the flight director shows the pitch over command. After it goes this cycle once, it works correctly for the remainder of the flight.

Any ideas?