Interesting, newswatcher, as that is what I have, but it appears that when BT 'enable' your line (in my part of the world, anyway) they 'spit' it, leaving you with a max connect of 19200 on the 'voice' part of the line which is what is used for fax (no problem) and 'dial-up' (problem).
I have not found a way around it yet!