i have to ask but are you placing a bowling ball on top of your iPod?
Normally, the belt clip is designed just to hold your iPod to your belt.... An unusual amount of weight or pressure would be an abuse of a design not meant to be used under extreme conditions.
I don't have a problem with my Speck ToughSkin....
Sorry to hear about your dilemna but I have to wonder how much pressure you were putting on it....