Having same issues with my cube. It used to turn off after a few hours, now it turns off after 30 seconds or so. Exactly same issues as described by the user (blizz3010) a few posts before my post. I also turned off my android phone and restarted my internet. Still the same. Any other suggestions ?
Got any screenshots of ur web interface settings and the proxy running? Also some tablets cause this issue.
And, as someone else said did you check the status of ur router and make sure its not close to the bandwidth max.