..and do you have the newest Java installed.
REcognize that some videos require ActiveX and/or Java applets to be enabled in order to run.. Firefox won't run ACtiveX unless you apply the plugin and many videos won't run as a result.
If you're using Internet Explorer as the browser, then please try the procedures in the link below to update the Windows Script engine and install the newest Sun java.
Java Installation Instructions...
Hope this helps.
When I try to play a video, I just have a black screen and no audio either. I have Flash 9, Win XP Pro. CNET TV works fine. I've allowed pop-ups and cookies. Now what????