@Soeasy , I think it could be a combination of a couple things. The first being, how often you use the cover. Everything wears out eventually but I do agree that things shouldn't be going wrong after only 6 months. You might just have purchased a slightly weaker cover or, maybe you use it A LOT.
All the covers that I've played with / used seem to work well. I would say, take it down to the Apple store and have a chat with them about the case. Maybe they will replace it, who knows. Don't think so but it's worth a try.
