ok, i'll try that. How can one tell if it's a clone or not, I'm not sure I trust the shop I buy from anymore, everything i have bought from them has been faulty in one way or another.
Like Panther said, the legit Plume Veils cost well over $100 - I've never paid more than $10-11 for any of mine, but in exchange I get these finicky problems to deal with like what you're describing. Mostly it's my wife that has the problems, I think it may come from either over-tightening the atty onto her mod (thus pushing the center post up and causing it to come loose) or the device getting banged around in her purse - she won't admit to either, but the only one I've had go bad got dropped from a height of about 4' onto concrete and landed on the drip tip.
Any case, try pushing the pin back into place and tightening the bottom screw up, making sure to leave about 1 mm sticking out of the bottom past the 510 threads, and see if it solves your wobbly issues at least for a while. You could also try replacing the o-ring around the center post, not sure if your atty came with any spare parts. For $10, I just call it a loss and chuck 'em when pushing them together stops working, for $30 you might want to put a little more effort in...