hi ,
Check out your APN settings here
UK apn - Saka Wiki.
For UK its..
Carrier:Vodafone (UK)
APN:internet
User name:web
Password: web
Carrier:Vodafone (UK)
APN:pp.vodafone.co.uk
User name:wap
Password: wap
Carrier:(pre-pay) (UK)
APN:pp.vodafone.co.uk
User name:wap
Password: wap