I fly my CX2's around in my basement, and I have steel support poles down there. I swear the magnets in the helicopter motors are so powerful that they pull the helicopter right towards the steel poles.
I have the Eflite lower rotor heads and haven't had any issues even after many of crashes, could be you got a bad one. I don't know why Eflite didn't make them all one piece.
Microheli also makes a lower rotor head, but I don't know how good they are.