BT do know what the problem is, Bill, it's just that they don't like telling you that it's their software that's duff.
If you have BT Broadband Desktop help installed, it might be worth uninstalling it; you evidently have a connection already and it is notorious inside BT for causing more trouble than it's worth, so I recommend you get rid of it.
Also, unless you're especially fond of the BT Yahoo! Browser, you can do with out it too. In fact, what BT neglect to inform customers is that unless they're connecting via USB, they don't need anything from the CD they supply. In most cases, they're better without it.