Don't worry, this is normal for the Corona. The first time I did a run up and tried tracking my blades I noticed this. It has something to do with the gyroscopic precession. When you lift off into a hover, the blades will tilt the way they're supposed to and the rotor head will respond correctly. If you look at a picture of any heli that's hovering, you'll see that for a stable hover, there is always a tilt to the right on the rotor disk as seen from the rear.