Hi I recently purchased a iPhone 4 locked onto o2, the wi-fi works fine, but it seems I have no 3g, I get the above message whenever out and about, I have been into settings and 3g and mobile data is enabled, A quick google of the problem seems to find many people with this issue, but no answers. I have reset settings to original state and rebooted but still no result. Any help will be greatly appreciated.
Call CS and ask them to change it to data for iPhone.
Then change your apn back to idata.o2.co.uk
I have no affiliation whatsoever with O2 or any subsidiary companies. Comments posted are entirely of my own opinion. This is not Customer Service so we are unable to help with account specific issues.