I bought a " Kick Punch and Crunch / legs and glute " DVD several years ago. I love it and use it quite often. Yesterday when I tried to use it with my DVD player it said "unknown disc" so I cleaned the disc and tried again. It still said unknow disc. Today I tried the disc with my computer, the result is the same.Seem like my dvd had expired.This never happened with my cathe's workout DVD. So I wonder if this happened with others and how long do I expect that my whole bunch of cathe DVD would expire. If I need a new one do I have to pay for it in full price or can I just return this one in.