It has been 3 days struggling with my Firefox, IE and Opera browsers to make YouTube work. I tried every suggestions found from many forums. Specially the uninstall, re-install Flash Player, deletion of Macromed folder and contents, re-install etc... None of these solutions works. It seems deeper than that. I also reset IE to factory settings, re-install Flash, reboot etc... Nothing works except... how strange, viewing YouTube in high definition... DailyMotion, no problem viewing videos there. Any suggestions? It is a a challenge, and many like me are in this situation. Hope someone comes up with the fix soon. Thanks!

I don't have a specific solution, but I have no problems viewing the site with all the browsers you mentioned which leads me to believe you may have a security program that blocks those types of sites using either a blacklist or filtering by image types.

Many sites also load their images/videos using JavaScripts and that must be turned on in your browsers. I know if I don't allow JS to run when viewing some sites, the videos will not play. I use NoScript add-on with Firefox which helps control JS on sites better. Just allowing the site temporarily allows the videos to run.

Ron

Ok found the problem: It was Google Web accelerator. Disabling it make YouTube video working. Seems to be a cache issue...

I see by your post that you found the solution. Good going and thank you for posting solution for all.

Ron