If your incoming /call-innumber shows as unknown number for new mobile, it is not your fault chaning the mobile phone configuration accidentally, neither the system update/flash into another lang version . It is possible that the service is not enabled by network. It seems unbelievable in UK, isn’ it?
Just call the customer service(orange) to enable you service, they will give u text , then just restart mobile , that is .BSD documentation licensed Free for non-commercial usage only
Author: Qingfeng XIA copyright (C) 2011-2013 http://www.iesensor.com
please keep the original link in your reference. http://www.iesensor.com/blog/2011/01/02/%e3%80%90solved%e3%80%91nokia-5230-all-incoming-call-shows-as-unknown-number/