Unable to lift off

EDIT: I found the problem

We have a problem with our QuadCopter.

See the video where the problem is shown with a small view off the QuadCopter on top of live data from MultiWii

I found out that if I connect my Bluetooth shield directly to pin 0 and 1 on the Arduino MEGA and set the baud to 115200, I was able to connect to the MultiWii software on the MEGA using this and MultiWiiConf.

It has been very helpful to be able to get data from the QuadCopter and film it at the same time. Then I have analysed different things afterwards. I have used some software which can record a application and webcam at the same time.

Well back to the problem.

I start by calibrating the ACC and then I arm the motors in Horizontal mode. The motors start running at 1180 which is my set min. throttle.

The throttle stick is at this point all the way down and reads 1094. Then I pull up one click and the throttle is now 1130. Then I don't do any thing. The front and rear motors are still running at 1080 but the left and right start picking up. And then it picks up more and more throttle even though I don't touch anything.

At some point the left and right motors gets throttle enough to lift the quad, but as there are almost no throttle on front/rear it will flipped over. I cut off the motors on the video before that happens. But before this video I have flip the quad over quit a lot.

Graph of the motor throttle - motor 1 and 3 and front/rear.

I have also tried to give more throttle, and it lift of nicely, but suddenly it flips over. So I haven't quit got to fly yet.

I will try to figure out what is wrong and return with a post when I hopefully have a solution :)

By the way the stuff from Hong Kong has arrived. So now I have stuff for to Quads but I think I will start by getting this one to fly :D Have broken 2 sets (4 pcs) of propels already so I hope I get a solution soon