I use the firmware v51.9.2 whereas it is the original firmware for the mobile phone of Nokia factory Initially after comfortable using the firmware, I can not use the features of the phone so that if I want to call somebody there is a notification of my nokia 5233 is 'no answer' and because I got confused this issue. I ended up using a custom firmware flashing RockStar Belle v7 specifically for nokia 5233 problem when the phone is no 'no answer' still exist I'm confused now. it should be if the phone is already in flashing the problem would not arise can anyone help me? sorry with my english