I installed the Slingbox M2 via WiFi through my Comcast Xfinity H DMIcable box. Now, it will not play anything on my laptop. Comcast Xfinity is also my internet provider. All I get is the black screen where the program SHOULD play, a menu on the side of all my cable channels...but nothing I've tried will get any program to run. Before this stupid thing costs me a front window, can anyone tell me what to do next?