On your device, go to Options>Advanced Options>Host Routing Table. Press the menu key and select Register Now. Then, pull the battery and allow your device to restart. Let me know if that helps.
I click on that and it says: Select an email setup option. I want to use a work email account with a Blackberry Enterprise Server. and nothing else. If i click next it says"Has your Blackberry Enterprise Server administrator provided you with an Enterprise Activation Password?" I click yes and then next and put in my yahoo email and password and click activate and then it says" Activation request failed. A service connection is unavailable."