From time to time changes are made to channel numbers to enable new channels to be added and to improve the TV guide on your TV.
On 24 February 2009 five channels are moving:
In order to ensure that you still receive these channels you will need to retune all your digital boxes and TVs on or after 24 February. If you have preset your digital TV recorder to record anything on these channels you will need to reset your recordings after this change.
New channels are frequently added to Freeview so it makes sense to retune on a regular basis.