Unlocked 9800 on Rogers App problem!

I recently bought an unlocked at&t 9800 and I am using it on the Rogers network. Most features are working fine BUT the Facebook, Twitter and App World App seem not to work while connected to 3G. They work fine when I am using WiFi. Does anyone know how to get these apps to work??
I appreciate any help!

Check your TCPIP settings (options->tcpip). You might want to change them to internet.com and leave the authentication to blank and unchecked.

Whenever I flashed my phone this was set to something else.

Hopefully that helps.