I've had my 6x11 for a good while now (6 months?). I recently rearranged my desk situation so I'm using it at a slightly different angle now. I noticed, since this change, that the grey rubbery-plastic piece that covers the actual "writing" surface is only secured near the top 1" or so. It's annoying because if my hand is sitting on the pad for too long, it sticks and pulls the piece up as I move. Is this normal, or is mine coming unglued? There doesn't seem to be any glue residue or sticky-ness on the underside, so I'm not sure.