Using my Cingular 650 GSM, with it acting as a modem, while on a Cingular network is rather straight-forward and works well.

This question is relevant to roaming in the U.S., on other carriers, as well but is less critical because I can find a Cingular network in most places. But what about in Europe and elsewhere.

There is a username and password that is used to log into the Cingular network. Now come the question about how this works when we are roaming. Say I'm in London or France on the Orange network or some other network. Does this DUN ability still function (without change) or will I need passwords for those carriers? I have used my Treo in England and France using my Cingular SIM without problems. I have even used email and data but not with DUN and my PC.

Anyone here ever try DUN (using phone as modem) while roaming on another carrier?