I just received my new 30D and 70-200 F4L lens. While handling the lens, I noticed that when I rotate the lens, there appears to be a slight rattle from inside the barrel. (That is to say, when I hold the unmounted lens in my hand and roll it so that the mount and objective lens move up and down.) I called Canon and they said to send the lens in for repair. In another forum, a couple of people posted that they had the same noise, while two more said that they did not. The lens is within a 10 day defective replacement period from the vendor, but I do not want to go through the expense and trouble of exchanging it, only to get another copy with the same, or worse, problem. I also do not want to send the lens in for repair and get it back a month later with a note saying "operates within specs". I thought I would ask if there were enough owners of this lens on this site to get a consensus of whether this is abnormal with this lens. Any help or information will be greatly appreciated.