Thanks for responding again Milhouse. As it happens, there are no supplementary AT commands listed (and I've never added any). I've manually configured for the 3 network as its not listed in the wizard that appeared when I added the phone.

Out of curiosity, I deleted the phone and selected O2 Mobile Web in the wizard after I added the phone back in the bluetooth devices. When I try and connect (expecting certain failure), I still see the same format AT command being sent , but this time with mobile.o2.co.uk. So, I'm surprised that you don't see it in your logs.

I'm not that familiar with modem command strings & scripts so I'm a bit clueless about this. I will note however, that I'm using Ross Barkman's modem scripts on my iBook, from http://www.taniwha.org, which seems to be the definitive Mac resource in this area, and the same command is used in them. Of course, the Mac doesn't connect all the time (maybe 50% of attempts), so I'm not sure there's anything to be learned from that.