A loose fit, faulty positioning of the sleeper magnet or any parts of the case becoming separated.

I notice you had a comment about the belt clip. This sounds like it is a problem also. Of course there are people who like or dislike the clip I use on my cases, but there should never be an issue with the clip not pinching together tightly enough.

Send me off an e-mail with all the details and I will make sure it is resolved.