Sorry I haven't replied in so long, but to be honest I missed your reply and thought the thread had died. I apologize for that.
No problem Carl, I've done that myself.
I've rebooted the router, and the downstream speed went from 224 kbps to 928 kbps! I don't know what the downstream attenuation and noise margin were prior to rebooting, but currently they're 63.5 db (I assume this is at the max, and is incapable of displaying a higher number) and 8.8 db, respectively.
Yes, a lot of routers can't display line attenuation over that figure. The 8.8dB noise margin sounds reasonable enough at the speed you've now achieved and the distance involved. I would guess what happened is that the last time the router connected there must have been some unusually high noise on the line (interference, an engineer working at a distribution point, etc.), hence it synchronizing at the greatly reduced speed.
Every time the router is switched on, it performs a handshake with the DSLAM at the central office to test the maximum speed which can be achieved with a given noise margin (the latter being configured at the DSLAM by your ISP). If the noise level on the line is higher than usual at the time of the handshake, then the DSLAM and your router will synchronize at a lower speed in order to meet the minimum figure configured for the noise margin. Reboot the router once the noise level has returned to normal, and you'll re-synchronize at the higher speed.
apparently Tiscali bought them out! I had a very bad experience with Tiscali so I wouldn't mind moving away from them.
I think it was about a year ago that Tiscali took over Pipex. I have a client in town who uses Tiscali for DSL at their office and for web-hosting, and I know it was sometime last year that I noticed a separate "Pipex customer login" option appear on the account maintenance pages.
They're only with Tiscali because they insisted on using the cheapest possible service available at the time it was set up a few years ago. I'm not impressed with either the quality of Tiscali's web hosting or customer service. Access to web servers is very restricted (can't edit .htaccess, not possible to set up custom 403/404 error pages etc.), the FTP server constantly drops the connection when trying to upload files, and so on.
I also ran into a problem with using mail functions from PHP scripts on their servers, with e-mails sent to addresses in their own domain simply never being received -- Ever. I never did manage to get that problem solved, since e-mails to their technical help section are ignored and phoning is a waste of time unless you just want to spend an hour talking to somebody who either doesn't understand English or has no idea of technical issues beyond the "have you plugged it in" script droids.