With the 257 and 258 computer bags, have any of you had issues with the zipper scratching your laptop or electronics? I'd like to use either the 257 or 258 to carry a 15" MacBook Pro, and also to put a camera insert inside the bag. My concern is that when I'm taking my camera or laptop in and out of the bag, the zipper could wreak havoc on the aluminum surfaces. If that's the case, I know I could avoid scratching by carefully removing and inserting my gear into the bag, but that would be kind of be a bummer.