My son who lives in Spain bought me a Ascend G610 which he gave to me when I visited him 2 weeks ago. WiFi connection worked perfectly in Spain in several locations. However it would not connect when we went to Portugal on our way back to UK (signal strength poor and authentification problem) and exactly the same problems having now returned to UK. I have used the same EE sim card in my old phone at all of the above locations without any problem. Can you suggest a remedy?