Dialup & Broadband Problem

Its a long story but basically in our house at the minute are several people sharing with x amount of people using dial up and the rest using broadband through the same phone line, the broadband is supplied by Virgin and the Dial up by Tesco.

The broadband functions fine but the dialup disconnects randomly, or does not receive web pages, does anyone know why this is or what can stop it?

I've heard of the ADSL filters affecting some normal telephone devices (e.g. modems.) I doubt that many people use BB & dialup at the same time. Can't you get a cheap router & put everyone on BB? There may be problems sending email, but receiving should be OK.