I bought this n97 but I'm not sure if it's unlocked because when I put my sim card from AT&T there's no signal unless I'm outside and there's barely any signal, this is not a problem to my other AT&T phones since I get strong signals inside and outside my home. Any suggestions what might b wrong with my n97? Perhaps it's not unlocked? Or something?

Warning : Do not enter any wrong unlock codes on your Nokia N97 mini mobile phones. If you enter over a certain amount of wrong unlock codes on your Nokia N97 mini mobile phone, your phone may get hard locked and sometimes become unusable.
1 - Switch on your Nokia N97 mini without any sim card.
2 - Don't bother as to what is displayed on your Nokia N97 mini.
3 - Compose #pw+CODE+1#.
4 - The Nokia N97 mini would then display the message "SIM Restriction Off" and will be unlocked!

Note :For Nokia N97 mini mobile phones locked to the network Fido or Rogers in Canada follow these instructions :
1 - Switch on your Nokia N97 mini without any sim card.
2 - Don't bother as to what is displayed on your Nokia N97 mini.
3 - Compose #pw+CODE+7#.
4 - The Nokia N97 mini would then display the message "SIM Restriction Off" and will be unlocked!

The letter p appears if you press the button star(*) three times quickly
The letter w appears if you press the button star(*) four times quickly
The symbol + appears if you press the button star(*) two times quickly
The CODE you need to enter is the unique unlock code for your Nokia N97 mini
Each Nokia N97 mini mobile phone has an unique unlock code. You can buy the unique unlock code for your Nokia N97 mini mobile phone from the site http://www.unlock-zone.com/