Okay, after giving my imei # to the cingular rep I got the unlock code for my phone. I type in *#*#[8 digit code]# and pushed the green button. I got the message "The Sim lock has been successfully removed from your phone." However I tried putting in an active SIM from another carrier and it says "The sim card you a trying to use will not work on this phone (I am paraphrasing but something like that)" and it says "No-Service - SOS Only" on the top.
I called back cingular and read them the unlock code they gave me and the new rep said that is the right code. So what could the problem be and how can I fix it?