i m heaving problem wth my iphone 4m last 1 week...i asked the solution at this forum...1 of my friends suggested me to put in DFU mode 2 restore...i tried it 2 restore via DFU mode...but it indicates at da screen ,this sim is not compatible ...insert the sim wch was came wth iphone.....i bought it unlocked like used iphone....is there any solution 2 solve this messege ( insert the compatibe sim....but it works wth all carrieres now....