Following are the likely solutions to this problem:
Check your signal meter to make sure you have a strong connection to the Internet (if you're using a WiFi connection, you can skip this step). Test your connection in another internet-based application (web browser, Facebook, etc.)
Switch Vlingo to use a different Access Point or Destination:
- Go to Vlingo Options > Settings > General.
- Click Network Destination.
- Select a different destination from the list.