It could be that your Sky+ or HD+ Box needs to be updated to the latest system level.
You should be able to do that via:
Using the buttons on the front panel / top panel of your box:
Hold down the power button until the Red LED Standby light is illuminated on the front panel of your box (If your box does not have 3 LED conditions Red, Amber, Green switch off the the power supply).
2. Press and hold the Backup button.
3. Whilst continuing to hold down the Backup button ,power up the box by pressing the standby button on the front/top panel of your box ( if the box has been disconnected from the mains supply reconnect the mains power supply). Wait for all 4 LEDs to illuminate on the front panel of the box .
4. Release the backup button.
5. You will be presented with the on screen message " Updating System Software". A system software update will take up to 10 minutes to complete.
6. Once the software update is complete the box will return to standby mode.
7. The box should remain in standby mode for up to 2 minutes prior to powering up the box