So I just set up a new wifi at home. My BB detects it fine and I get the wifi icon on the right corner. When I go to load a page it will load the first one fine. Then I get a white BB screen with the pop up "A problem occurred while trying to render the page."
I've used it in wifi mode a week ago at a friend's house with no problems what so ever. I've tried resetting the factory defaults for the BB browser and I did the battery pull. I also deleted the wifi profile on the BB and redetected it.
It is the tcp server that TMO uses for internet access. It is blank until you set it up. It is a learning curve like everything else. Wifi prefered makes it so wifi is preferred first and then it will go to edge if it does not detect wifi. Glad it worked for you and I could help..