Been flying a new BCX2 since Christmas getting progressively better while spending money like a drunken sailor at my LHS on parts (mostly blades).

Anyway, my latest problem is proving to be incredibly frustrating and I'm hoping to tap into some of the expertise here to help me solve it. I'm having some severe wobbling problems at any kind of RPMs. I have narrowed it down to the very top blades/flybar. Basically, I get absolutely no shake at all until I assemble the top blades & flybar. Everything else is true and tight - just as it should be. The blades all fit extremely smoothly and move without any resistance at all. Likewise, when I attach the flybar everything is super-smooth. But the thing shakes like something is very wrong. I bought a brand new flybar today and put it on - it flew great until I tipped it over on the floor on a takeoff. After that, everything was a disaster. I barely touched it - this wasn't even a crash, but it is unflyable again. The flybar, when pulled off the helicopter, rolls smoothly and doesn't appear to be bent. As near as I can tell it is well balanced, but it sure seems to be the source of my problems. Can anybody give me some advice?