I ordered some new blades, which I put on my vision 2 today.. But I noticed the blades are different than the ones that came with the copter.. They are DJI Phantom part no. 26.. The blades appear shorter, and more rounded.. Anyways, I'm still getting a vibration when I'm flying.. I can see a slight bit of wobble (dipping down), between the left and right sides .. I can also hear the motors continually correcting-- ie: ongoing sound changes-- as in change of pitch.. What could be the problem? Wrong props for copter? Out of balance props? Bad motor? Bent shaft? Bad electronic component?