The issue here is the EPG data, specifically the first-aired-date/episode data.
The vast majority of the time, this data is present and enables your box to schedule recordings based on "this episode is new" or "I've recorded this before".
Occasionally this data is missing, and TiVo errs on the side of caution and will record the episode - this is by design.
If you see programs in the EPG with either missing or incorrect episode data, you can email them to firstname.lastname@example.org - you won't get a reply but the errors tend to get fixed within a day or so.
I'm a Very Insightful Person, I'm here to share knowledge, I don't work for Virgin Media. Learn more
Have I helped? Click Mark as Helpful Answer or use Kudos to say thanks