I am doing research...
Are you an Australia BlackBerry user?
(1) What model do you have?
(2) Have you upgraded to BlackBerryOS version 4?
(3) Do you have a full HTML browser, or only a WAP browser?
(4) When you configure Options->TCP->APN to "telstra.internet", can you run software such as VeriChat? (VeriChat is instant messaging software. You can download and install wirelessly by entering http://www.verichat.com/ota/VeriChat.jad
in the BlackBerry browser...)