Recently, after a post on whether the rails loosen over time, I decided to give mine a try. Holding it by the tab, I shook it. Lo and behold, the Kindle slipped down about an inch. Thank goodness I had the foresight to do this over the bed and as well as the fact that it didn't fall completely out. So I took the Kindle out, pushed in on the rails, both top and bottom and put the Kindle back in. Had to do that a couple of times because I didn't want to push in too much. Now the Noreve is good as new. It think it does loosen over time and with use although I rarely remove my Kindle from the case.
Anyone with a Noreve might want to do this quick check-up from time to time. You know... better safe than sorry.

Vicki