hi there,
apparently in the settings menu somewhere, there is a setting you can change to stop it automatically going to standby after a certain time but i'm not at home at the mo so cant have a look where. I would be worried that its not recording programmes when in standby mode though, as i record quite a few things late at night and overnight and always put my box on standby when i go to bed and have never had this problem. afraid you might have to ring sky - good luck!