SKY + HD BOX GOES ONTO STAND-BY.

I hope someone can help me.
My sky box, non sub, is linked to a DVD recorder. I set the recorder up to record progs on one satellite channel over 4 days of the christmas period and left the box switched on, set to the correct channel.

When I got back after the holiday the recorder had recorded a blank screen for each day because the sky box had put itself into stand-by mode!!!
How do I prevent this from happening again?

Any help will be appreciated.