I can't offer any theories but I can tell you that since I got a Bluetooth wireless keyboard and mouse, I've had more grief than you can imagine. And, of course, Dell refuses to send live tech support. I had the entire tower taken apart and strewn all over my floor while talking to tech support on the phone. Four and a half hours later, the problem still hasn't been solved. They will only send live tech support if it's a hardware problem and they claim it's a software problem. So I have my old computer guy on standby should anything happen again. I will never buy from Dell again. This computer is only a year old.