Loss of wireless internet, once ethernet cable is plugged in

I am at a loss as I have used my Macbook many times to hook up my Xbox to the internet using my ethernet cable. I have not changed any of the settings that has made this connection work previously and I am running into a problem.

I am staying at a hotel and am logged into their wirless internet. The internet seemed to be fine prior to plugging in the ethernet cable (connected to the xbox) but the moment the ethernet cable is plugged in, the internet stops working (still full signal to the wireless router) I have checked the priority in network settings and still have Airport as the top priority with ethernet second.

Again I am simply trying to share my Macbooks internet connection with the Xbox via the ethernet cable. Could the hotels router settings prevent sharing? Any other help would be greatly appreciated as I have 4 more days here...