Sim Failure?

[nizzex]

Hi.

ok, this is how it is.

I got an iphone 3g, I used this tutorial for the unlock:

http://www.iclarified.com/entry/index.php?enid=2538

I did everything, but when I take out the o2 and put a different network one in, I get 'Sim failure' and no network.

Can someone help?

EDIT:
Went into Settings > General > About and got my iPhone info:

Version: 2.2 (5G77)
Carrier O2 2.9
Model: MB496B
Modem Firmware: 02.30.03