Hummingbird trimming

[arctic sailor]

A week ago I received my new Hummingbird. It came with the mixing/gyro board. Everything is running OK except it seems I can trim the tail so that the helo stays stabilized. I tried different gain/mixing ajustments but the closest I achieved is full left trimming on the tail servo and still I am missing a few clicks and have to use the stick to compensate on take off.

I double checked the installation and everything is in the right position.
Any ideas you micro helo enthousiasts?