In high volume periods of traffic, you'll find that you isp will start using its contingency measures to try and smooth the customer experience.
Unless a cable network - BT still own all the technology - which is why they are the only way forward.
The networking of the UK should be (re) nationalised, but thats another thread.
Thanks Dan, never looked into the Google Public DNS - although I dont like google - I love them. . . so efficient, so right, . . .

Baz