It would seem that in Knowsley near Liverpool, Virgin Media cable customers who subscribe to the M (up to 2Mbps) product have a lower upstream speed than the rest of the country. Their cable modems are configured to connect at 200Kbps for the upstream, rather than the standard 256Kbps. The Register has more on this including the following response from Virgin Media.
"Since merger we have made significant progress on integrating and improving our legacy systems. So far we have completed a massive billing centralisation project, launched a new 20Mb service and upgraded customers to higher broadband speeds for free. Work to align minor differences in speeds across the NTL and Telewest customer bases is ongoing and should be complete very soon, along with further initiatives to reinforce our position as the UK's leading residential broadband service. We apologise for any confusion and will be updating our website accordingly."Virgin Media Statement
For many broadband users the upstream speed is relatively unimportant, but for people hosting games, uploading videos/photos or running devices like a Slingbox a reasonable upstream speed is critical. The advertising focus is heavily on which provider sells the fastest downstream speed service, but our forums suggest there is a sector of the market looking for faster uploads.