The rattle is perfectly normal when the camcorder is turned off. It has a tiny gyro in the stabilization mechanism that sort of flops around when not powered up. (most camcorders with a good stabilization system make the same noise) The rattle goes away when the camcorder is powered up. If the rattle is still there when the camcorder is turned on you have a problem.
Hi - I do not think this is "normal" - mine didn't rattle - that sounds to me like the camera has something broken inside. I would return and get a replacement. It may work great now....but what about the future? However, I am no expert. Best of luck