Pace Sky+ box?

My box keeps going into stand by mode then wont switch back on I have to unplug the power sourse and leave it off initialally for about five minutes but now its getting to be for a couple of hours before it will switch back on again, when it does come back on all recorded programmes have gone and sometimes it wont record saying Sky+ features are not available and to ring the on screen number, which I have done and all they do is a full system restore and it worked a few times know even that wont work, any ideas