I have a Compaq DeskPro with XP Pro. Videos on MSNBC and other "click to play" sources usually work fine. You Tube and Hulu, however open first image and stick there, as audio continues. I am on cable modem.I've uninstalled and re-installed Flash Player - to no good effect. Could it be the Video card?
At times, videos from various sources are jerky, or freeze 'n go.