Thanks joe83. The site itself was not helpful as the modem is not a WinModem, but it did lead me to
http://www-106.ibm.com/developerwork...aq/?nl=swalert which has a 50 page (pdf download) manual for Newbies which did help.
I have a Winmodem and the external modem and the manual told me how to select which modem was to be used (kppp) so I have resolved the problem.
This does point out one of the failings (?) of Linux for Newbies in that programs have non descriptive names (eg "kppp" instead of "Internet Connection") and often has 2 or 3 places where a "similar", but not always the same configuration can be made; and which are not usually grouped under a common folder (eg Systems/Hardware Configuartion/.......). Just a bit of a gripe - I am using Mandrake 10 which is far superior in this respect than the other earlier distros that I have used.
Again thanks for your help.