Banned new nokias

Hi there!
I´m just vondering if theres any possible way to change the IMEI number on a 8310, 6210?
I´ve heard that nowadays theres one IMEI in the eeprom and one in a prom or perhaps rom, and that the phone compares these in the initiation moment when the phone is powered on and if these numbers aren´t similar the phone will be banned.
Is this true? If so, is there any other way to use banned new nokias?

I haven´t been in this cell-phone scene for a while and much have changed since last so I would be very, very happy if someone could help a lame idiot like me.

Millions of thanx in advance / ece