Has anyone else had a problem with the premixes on the DVDs? The first time it happened, I had it replaced (purchased from collage video), the second one had the same problem all though in a different spot. When I contacted Cathe.com, the person told me to clean the DVD and DVD player - I did both and still have a problem where the DVD freezes in different spots - I have to fast forward it to get to the next move, it happens enough that I really don't want to use the premixes. Any wisdom?