i live in the hull area which is served only by kingston communications under the Karoo banner.
It uses different VPI and VCI nos, etc to BT based offerings and is very sensitive to the quality of the equipment used.
The only brand that works constantly unfailingly is Netgear and is in fact recommended by Karoo.
I changed from a D-Link which was always losing connection to a Netgear DG834GT which is proving to provide a very reliable connection.
Furthermore, for anyone not technically-minded, it detects the line settings automatically making installation a doddle.
Can't recommend it too highly, well worth paying that little extra for.