I just got my iPod 2G about a week ago, and I noticed that the seal between the the metal body and the glass is not correct. When I press on the corners of the unit, there is kind of a dull "popping" sound and you can see the glass compress into the correct place. Is this a common defect? Is it enough of a defect for Apple to fix or replace under the warranty? I don't want dust to get through and collect under the glass where I can't clean it off.