Just before I came back to Argentina 18 months ago, I bought a nexus 4 sim-free/unlocked phone from carphone warehouse. When I arrived back in Bs As and before I smashed the nexus' screen to smithereens I was unable to get any sort of 3g internet coverage when i added my movistar chip. Movistar scratched their heads in their normal fashion before giving me a new chip which produced equally poor results. After the smashing of the screen, I purchased a phone from Garbarino (again sim free) and put in my movistar chip and 'de repente' the internet coverage started to work. So......was i just unlucky with my nexus or will all phones brought in from the uk have the same issue. I ask as Im about to go off to visit my mum and i rather fancy another splurge at carphone warehouse.