I've got a first gen. stack-mat that I have been using until not so long ago. It started acting weird. After I would reset it, and when I released my hands for the next solve, it would freeze at the zero second mark, right where the screen flashes that sort of greenish color. I literally have to turn it off and on again every time so that it won't freeze on me when I start it. And even then, I have to act quickly after I turn it back on or it will still freeze for most of the time. I assure you I have used everything correctly. Should I get a new stackmat or try to fix this one? And has anyone ever had this problem before?