Okay, since Vodafone don't seem to know the answer, i found it out from a UK site (blackmarble.co.uk)
"The problem is down, as I had suspected, to congestion in their WAN network (not the 3G network, though the density of cells is a factor). When you try to use HTTP Vodafone route a request to their authentication server to see if your account is allow to connect to the site. By default they block a list of adult/premium web sites (this is service you have switched on or off with your account). The problem is at busy times this validation service is overloaded and so their systems get no response as to whether the site is allowed, so assume the site you asked for is restricted and gives the 403 error. Once this happens you seem to have to make new 3G data connection (reset the phone, move cell or let the connection time out) to get it to try again."
Probably a bit too much to ask - but any chance this can be looked into ? 1) to fix server capacity so that its not overloaded and 2) fix the fact that once you get the restricted message once that you don't have to reset your phone to work around a Vodafone problem
Did i read right that Three and Voadafone are to share architecture soon ? It will be delightful for finance departments to see synergies saving them loads of $$$ - but what of the poor customers who are already getting their 403 errors ? I already know the answer - EVERY decision nowadays in business and government is made based on $$$ first and customers / people second.