OK, So I got a PS3 and got MW3 with it. I made a psn and everything. When I play the game it works for some time and then crashes and gives me a black screen, other times it just frezzes and I have to turn off my PS3 and start it again. I can't lv up or anything. I called Sony about 3 times and all the 3 times they told me to call Activision or go and try to get help online. I got a demo and it worked fine no lag, crash or freeze, can any one please help me?