Try these suggestions
1) check settings and rules in the Windows Firewall or your 3rd party firewall (if you have one) to see if any video streaming or the like is blocked. Also, check the hardware firewall (router) for any unusual settings
2) have you recently had a virus or spyware that was "cleaned"? Maybe your security software blocked any flash content.
3) uninstall your flashplayer & shockwave player and reinstall the latest version. You will need the Firefox version AND the Internet Explorer version. Get the uninstaller from here:http://kb.adobe.com/selfservice/viewConten...7&sliceId=1
I would strongly recommend you update your definitions and run virus & malware scans in Safe Mode and also post a Hijack This log in the forums.
I have a feeling that you're infected somehow.