Whatever the engineer did seems to have fixed the tv issue.
My main gripe now is that I'm still being charged full whack for a TV service that for an entire month was close to unwatchable (check the video I linked above).
To be honest, you guys and girls answering on the forums have been really helpful, however the arrival of Virgin Media in our household had brought with it nothing but problems (we're now 5 weeks on since installation and our Internet service is still abysmal). I fully regret leaving Sky, and unless something improves drastically in terms of the service (and the matter of billing us accordingly), I'll be heading straight back to Sky.
As of this moment in time I can truly say that there is nothing I can recommend about Virgin's TV or Internet when compared to our Sky service.