Hey guys, i need your help. I just got home and received my brand new P25. Ive been having super bad luck with this lens. but thats not the point now. The lens looks great, but it makes a really weird sound when focusing (that i dont remember from previous copies ive had from this lens (this is my 4th copy). is not the "blade chatter" that we know about the P20/P25 cause the blades are not chattering, BUT is like a really hard focusing noise. not sure if the lens is faulty or if its fine and nothing to worry about. check out the video and listen closely. https://dl.dropboxusercontent.com/u/1030775/VID_20130618_184132.mp4 appreciate your help!.