HTC Vivid problems after upgrade

Hello, I need some help. I have a  HTC Vivid, phone was perfect, but after an upgrade I got problems. When changing from one application to the next the phone gives me a white screen with HTC logo in it, then it turns dark with a "uploading" window. I wait for about 40 seconds before i goes from reading messages to brouse the Internet or making a call or anything. Please help.. how can i fix the problem?