Hey I just got a Xbox yesterday. I'm having a similar issue. The kinect seems to be working fine when the system is on (granted it's less then 24 hours old) but when I put it into sleep mode and try saying Xbox on it does nothing. I hit the power button the Xbox fires up, and I get the message kinect unplugged. However If I unplug and plug it back in it comes back to life. Did you ever experience this? Did you ever get your situation resolved?