This has been posted in many forums.
EDIT: I have successfully installed N70ME firmware on my phone.
I changed my PID to 0536418 and updated the software. Now its working fine. After changing the PID and launching NSU, it says software upto date if you have V5.0638.3.0.1 already installed. You have to ignore that message and select reinstall option.
Another thing, I can easily change my PID back to the original one i.e. 0524128. So no problems.
I don't think this will void the warranty.