Otherwise, as a last ditch attempt to fix it yourself before you part with cash - you could try a forced software download. It may fix any possible software corruption.
1) Put TV on. Put Sky on.
2) Hold down the Back-Up Button on the main box.
3) While it's depressed - disconnect the 'mains' power completely. (BUT don't let go of the backup button yet!)
4) Wait 20-30 seconds, when all the front display lights will illuminate on the Sky box & a messgae will be displayed on TV.
5) Only then release the backup button.
6) Wait 10-15 mins for the download to complete.
Cobweb, May 2006