I agree with newbie, get a LiPo because the NiMh is too heavy.
3D, are the flybar paddles level?Do you have a head stiffener?
Aero Newb, the swashplate on most will not be level, they have to be trimmed to one side or the other to fly right. Very few are going to have a perfect weight distribution for a level SP.
Bmratc, there is nothing to it. When you open it up, there is a metal tension bar on against the back of the stick. You can move it or sand the plastic teeth off the stick and put it back. There are not alot of parts in there to deal with.
Although i have made these changes myself, i still get a floating hover. I was told it's wind current in a small enclosed area. Could be my CF blades are a bit worn out also. New ones on the way so i can tell.