Well I guess joke's on me if it is truely defective, but I bought the sentry 2 for the second time now and have the exact same issue as the first one did. I have it all connected as it should be, and I have about 3 seconds after supplying power to it to actually change and select anything on it before the touchscreen becomes unresponsive all together. Am I doing something wrong or is this thing just defective too?