Hi my friends..... The problem is not the sim. The problem is the baseband chip ! This is the one that gets hot ! The phone searches for signal and even it is to low or nothing at all especialy in places with low signal ... If you put your phone in airplane mode you will notice that it works perfect ! Thats the reason it doesnt gets hot because te baseband chip turns off in airplane mode . When you notice that the battery latst for not long time it is because the phone tries to find signal and loads all the energy that it can to find signal... And takes more energy from the battery to do that.... .... I beleave that the baseband chip is defected somehow possibly by drops of the phone .... With this as guide if some one finds something better it would be very nice ! Thanks