I've been having problems with my 4gb 360 Slim lately. It disconnects from Live pretty often. It does this whether I have it connected via ethernet cord or wireless. If it disconnects, I have to turn off my console and turn it back on to get it to connect. My NAT type is open and it can't be my internet because everything else stays connected when Live disconnects. I put the hard drive from my old Xbox 360 into it if that matters. I wasen't sure if there was anything I could do, or if I have to send it in.