My internet works .... apart from bbc.co.uk

Silly question, as it may appear, but do you have any trouble accessing microsoft.com, or mcafee.com?

Both of those sites load fine. In response to your previous post, I don't have any of the items listed installed apart from the firewall which is integrated into ESET Smart Security v4 which I have, I disabled the firewall module but still no Beeb. Edit: Clearly I can't access the Beeb but I can ping them but out of curiosity, could a firewall potentially block a ping if I felt like blocking pings (not that I would want to)

EDIT: The Beeb now works yet I have no idea why it's suddenly working now. Coincidentally, there was a power outage in the house today although I highly suspect that a power outage has nothing to do with the BBC site now working.

That's good. Unfortunately, I can't say why you were having problems either. My only other suspect would be malware, or Eset. An uninstall of Eset temporarily may be needed if you have the problem again. That's about the only thing else it could be. To answer your other question, yes, a firewall can block any kind of network traffic based on a set of programmed rules.