If you have found that certain channels are missing, this could be down to channels being taken off or replaced.
You could try retuning the digibox:
1) go to the services menu using your remote
2) enter 401 on your remote and press select
3) press the 6 button or whichever button and select new installation
4) obviously if dish is correctly aligned, press select on remote
5) see if you have a good signal and good signal strength
6) press select on the remote and should retune all the channels
7) after tuning, press select it might ask you to insert sky card
8) press select and this might have retuned the channels.
kenno, May 2010