Logging into Google

Hi all
When trying to access the Market app i am prompted to log into a google account, or to create one. I have already set up a Gmail acct on my pc so attempt to log in using this.
However, every time i get a message saying "cannot establish a reliable data connection. this could be a temporary problem or your phone may not be provisioned. Please try again blah blah"

I contacted Vodafone who sent me a PDF to do with WAP settings which has had no impact at all. Helpful

Any one got any ideas?