High buds, I just received my very first HPS. It's a Philips SON-T PIA Plus 400W bulb. I haven't connected yet or anything. Funny thing is when I rotate the lamp over it's axle in my hands, I can hear metal touching glass at a certain angle. Is this normal? I can't see any loose parts inside the bulb or any other damage or movement, but I'm certain something is moving because I hear it. So big HPS noob question is, is this thing supposed to make this sound when I rotate it?