firefox browser not play in youtube

guys please help me.,my firefox browser can't play youtube,i'm trying to updated to latest version but same not play i also try to uninstalled and then reinstall,i try also update the adobe flashplayer javascript is enable.i try internet explorer no problem for youtube,why firefox can't play......

Does flash show as working in FF?

Find version | Flash Player

Sounds like a cookie issue. Make sure you have FF set to accept cookies form youtube. You may also have to accept 3rd party cookies

Enable and disable cookies that websites use to track your preferences | How to | Firefox Help

You might start with deleting the current youtube cookie if you have one

Delete cookies to remove the information websites have stored on your computer | How to | Firefox Help

A Guy

Edit, just remembered people were having problems with flash and Firefox

http://forums.adobe.com/thread/1018071?tstart=0