Virgin Media iPlayer != BBC iPlayer
The content on Virgin Media's own iPlayer service is nowhere near as comprehensive as the BBC's own service. We usually end up using the Wii to watch iPlayer through the telly, as the Virgin Media service seems to
a) only carry the shows that VM used to carry on its on-demand service before iPlayer
b) be its own-recorded shows, rather than pulling content from the BBC iPlayer network
c) have about 10% of what BBC iPlayer has
d) only carry every episode of Bargain Hunt, etc
so basically you're looking at a Virgin Media service that's just been labelled as the BBC iPlayer, probably to discourage people from using their Virgin Media pipes to access the content instead.