I did not do anything differently with the disc at all. Just put it on the shelf as usual . I looked through my online orders and found out that I ordered it from collage since 2005. I emailed them already. let's see the result.:p
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...