first thing to check is that they are properly engaged and not just slipped up on the end. mine does not move or make any noise at all. in fact, mine are sometimes hard to pull off because they grab so well. I use CA glue on my screws like we use locktight on the heli, and I have never had one start to back out yet, and I have hundreds of flights on my N7's.
again, first thing I would check is to ensure that they are properly engaged. it is very easy to quickly push it on and the channels not being pushed all the way towards the frame. does that make sense? you have get them "half" way engaged by not being sure that the post is 100% into the channel, not front and back way, but side to side way....that could surely cause a loose condition.