Thanks TG, I hadn't even thought of that one but I've now checked and the line isn't CLID protected.
FL310, Connections to internet are fine, IE5 works fine. OE starts up OK and tries to send and receive messages but then says it's failed and come up with the error messages as above.
Tallbloke, ISP's are virgin & greatxscape.
Thanks for the input so far guys - anyone else have any clues?