Please retune your television, you can do this by choosing Menu>Setup>Auto Tuning.
If this doesn’t help check your antenna cable (unplug the cable and then re-connect it)
Also check whether another digital TV works fully on the same aerial; if not then you may have an antenna problem. A professional aerial installer can advise you.
Please note: During digital roll out in the UK, you may experience temporary problems. We would recommend checking the digital website for local information (http://www.digitaluk.co.uk/)