Dear Nokia, I bought Nokia n79 on August, 2009 from RAYA shop at Obour branch and at the same date of my purchase i found my mobile while it was working normally or making a call " the operator signal cut off then it appears to me sim card registration field and there is no choice except ok and when i press ok appears a white screen with the following message insert sim card" so i have to move the battery to restart the phone i went back to the RAYA shop to ask to change the phone he refused to change it until i change the sim... read full review »