As Miss-taken suggests, re-tuning your Freeview box should fix the problem. However, I'll add that when you're given the option of 'add new channels' or 'replace exising channels', you should choose 'replace' rather than 'add'.
If you want to check whether you're tuning is currently up-to-date, take a look at channel 35. You should find a screen advertising 'Five US: Coming Soon'. (Similarly, channel 36 should be advertising Five Life). If you don't have these ads, your box definitely needs re-tuning.
Chris