Need help setting up AIM on 3390

Hello, I just recently got given my moms old 3390B T mobile cell phone, I had to unlock it to use my cingular sim card from my old 6190. Iam trying to sign on to aim but it just won't work, I set there preferences right, I checked 3390 AIM, CINGULAR WIRLESS and I got texted there activation code but It wont sign in, I got this message later,

14690 Unknown carrier Your message was:015A003EFF5C02000038011E0901013C0805008C4465766F6E4E6531736F6E0070656E7469756D32004E4F4B49412C33333930622C535730322E3033

Dont know what that means but Any help is appreciated