I'm at a loss here and need help. Lately, my trex450sa looses tail authority and wants to pitch backwards to the left when the nose is facing away from you. Everything will be going fine and suddenly I have to give it more and more right tail imput. I can be giving it full right stick and it still doesn't respond. At first I thought it might be the batteries, wrong. All the linkage seems fine and is adjusted correctly and the servo is mounted properly. I'm using a hitec hs-81 or hs-85 servo for the tail (I'm at work at the moment). I have the tail servo mounted to the servo brackets using the rubber gromets with the brass piece going through, should I have it mounted a different way? Also, I'm using the disc instead of a servo arm but it seems to have the full range of motion. The one thing I noticed was that one of the tail rotor blades was looser than the other, I'm thinking that that could be what's causing it. I'm not doing any 3D flying, mainly just hovering and straight and level flight. Has anyone had this problem or have a clue as to what's going on? Please help, I'm tired of crashing because of this. Thanks!