What is the Restriction Code?

[Glenhey]

I have a Nokia 6230i originally locked into the Tesco network (UK) and I want to use it on O2.

I used the NokiaFree.org site to get unlock codes and, on using the first code, was told that it was successfully unlocked. But, after putting the SIM card in and entering the PIN code, I am asked for a Restriction code - if I enter the code I used from the site, it tells me that the phone is already unlocked, but then asks for the restriction code again - if I enter a different code (from the list) it displays an 'error code' message and then returns to asking for the Restriction Code.

Any ideas on how I get out of this vicious circle?

[NokDoc]

Hi,

Probably it wants the phone's security code now.

On top of the screen is a link to calc a 10 digit mastercode to use there in case U can't recall Urs anymore.

NokDoc