error starting vlingoforblackberry_en:Class'net.rim.device.api.ui.decor.Background' not found
is caused by downloading a version of Vlingo that doesn't match your BlackBerry's operating system. The easiest way to solve the problem is to re-download Vlingo from www.vlingo.com. Be sure to use your BlackBerry's built-in browser. This will automatically detect your operating system and send you the correct version of the product for your phone. Once the download is complete, you'll be prompted to reboot your phone.
If you had purchased Vlingo Plus for this BlackBerry, you will not have to purchase it again.