Motorola RAZR V3

Hey guys. I have a weird problem with the AIM feature on my RAZR. Here's the deal: I can sign onto AIM using one of my screen names, but the screen-name i want to be signed onto throws an error when i try to log on via my phone. It says that the server is not responding or something. Is there anything in my AIM properties that i need to adjust to be able to log on from my phone?

Thanks in advance,
James