Error connecting to a broadband connection

I have a broadband connection coming into this room, with a broadband router plugged into it. There are a variety of machines plugged into that, running Unix, Windows 98 and Windows XP.

I'm out in the country, so may well be at the limit of what is possible on broadband, but the unix and windows 98 boxes seem to see the outside world happily enough (though I could persuade my self that there are odd occasions when they seem a bit slow).

But the XP box is a different story. Quite frequently it seems to try to connect to the internet itself -- this happens either if the response from a web site is a bit slow or if I have mis-typed a URL(!).

For a while it was trying to establish a dial-up connection (as it had formerly been connecting over a modem and still had the connection installed). So I uninstalled that connection. It then went through a phase of trying to dial up which seemed to assume that there was a broadband modem (none has been installed), and now it pops up a dialogue box saying:

Error connecting to a broadband connection

Connecting through the WAN miniport

Error 678: The remote computer did not respond...

Redial cancel more info

at which point it simply sits there, with the "redial" counting down in seconds. Most of the time, if I simply hit "cancel" then everything works -- this supports my suspicion that it is being triggered by a momentary hiatus in contacting the remote site.

Under Network Connections (accessed from the control panel) I seem to have three connections: one "Broadband connection" on a WAN miniport (PPPOE), and two "LAN or high-speed internet" internet connections, one through a "1394 Net Adapter" and the other a "Realtek RTL8139 family..." --- I'm not aware of having installed the "Broadband connection" and guess that the others are associated with the network card.

Can I simply uninstall the broadband connection, on the grounds that, although the network is connected to the internet over broadband, the XP box itself is connected to a router and not directly to the internet, or does this shaft my connectivity? Or is there something else I should be doing?

Thanks

Mark