here's a question, on what axis is the heli shaking? if its in the yaw axis, its the gyro sensitivity. however, if its on the pitch or roll axis, the first thing i would check is the tightness of the blade grips. the main blades should not be free, but be able to be pushed back with a little force. the reason for this is so if they are not perfectly straight, centrifugal force will pull them out to the proper alignment. i have experienced this myself and as soon as the blades straightened, it was smooth flying. good luck and keep us posted.