After starting the Phantom 2 ver 3 the GoPro 3 zen muse 3h 3d gimbal, camera always faces vertically down. I can control it with the thumbwheel to bring it horizontal and move it through 90 degrees vertical.
I have calibrated it in the Assistant software and have upgraded all software and hardware.
How can I get the camera to face horizontally forward at start up without using the thumwheel?

I calibrated my camera wheel in the "DJI Phantom 2 Vision Assistant_3.6" and I can control the speed it goes from horizontal to vertical by the amount of turn I put on the wheel.   In the "basic" page of the 3.6 app, select "rc" tab.  There you will see 2 calibration starts. "Command sticks calibration and sticks monitor"  You only need to start the command sticks calibration and do all the calibrations including the camera wheel.  You do not need to click start calibration on the "sticks monitor"   I can vary my movement from horizontal to vertical from 2 seconds with maximum movement on the wheel to 45 seconds with a very little turn on the wheel.  Make sure you select upgrade version.