If you have iOS 4.0 and the internet will not work, then DO NOT TRY the tutorial here for you will end up in the situation of having to restore in order to use the Internet on the iPhone. Yesterday I made the mistake of activating the cellular data network option on my phone and after a restart the internet refused to work on Orange, in fact the option disappeared altogether. With a card from a USB stick from RDS I managed to make the internet work, but on Orange it refuses so I had to restore to solve the problem.
I don't know if the problem also applies to those with an iPhone 3GS, but theoretically it should, so be careful how you travel with Carrier Bundles, because you might find that the internet won't work anymore.
This change applies only to those who use the phone on Orange because the rest who use it on Cosmote/Vodafone/RDS already have the Cellular Network Data option activated. The option does not appear for those who use the phone on Orange, because Orange is an authorized reseller and has ready-made carrier bundles in iOS.
