Why do Freeview do this?

Can anyone tell me why Freeview insist on putting up a none cancelling flag at regular intervals to say that channels have been added or removed? It might be policy to give out information but it makes it a real hit and miss afair to record a program using a timer because almost inevitably there is a flag across the picture which wasn't there when the recorder was set! I have had countless recorded shows made unwatchable by them and I can't be the only person it annoys.