My recently bought iPhone 3G (from a third party), is not connecting through the 3G network (Virgin Mobile in the UK). Everything is switched on, 3G, Mobile data etc. but it just wont seem to work. I am using a SIM card taken from my BlackBerry phone.
It's really frustrating because I can't use the intternet whilst I'm outside and must wait until I connect to a WiFi.
What is causing this? What can I do to solve this issue?