Imei change for N81 & trend failed..
 

I tried all of my best but I was unable to change imei for N81 and trend mobile today. I have changed alot of imeis for others sets. but these two sets were booting ok, Read flash ok, Flash Ok, Format ok but when I pressed direct imei button then I turn on phone. Phone turn on ok but the software message me
Original imie read error
Write new imei error...

What is the best way and corrct way for these sets...