It's because the box has just been installed. To get you up and running as quickly as possible it will initially only download a couple of days of listings. The rest should appear automatically at some point, probably in the next few hours. If you don't want to wait then you can force it to download the latest listings by going to Help & Settings, Settings, Network and then selecting Connect to the Virgin Media Service now. It may take a while to download and then process the listings, especially on a newly installed box. If you're not in any hurry then just leave it and it should update automatically.