Ste, Southsimon, thank you both for your help, very much appreciated - I'll try again with a new box!
No problem - plenty of useful info in the cable receiver faq and the h2.h setup guides in my sig for you to peruse also ;)
Have you set V*rgin UK to yes in Autobouquetsmaker and put your area in there also?
It's not impossible for your connection to be disconnected - rarely happens but I have seen it where a VM installer can't be bothered running another cable to another property so steals it.
Are you friendly with any of them? ... maybe they would let you try the box in their house.
That's correct - 1-5 (SD only) will work without internet.
I'm sure if you took them a box of biscuits and politely asked them would they mind if you tried your virgin tv box on their connection as it isn't working in yours and you want to know if it's a problem with the box or if to call out V*rgin, they should be accommodating... if any of them have a TV box too, you could check to confirm the net id is 100% correct :)