Hello dukeomegaThere is a known issue involving Firefox and Flash 11.3x and Youtube.Please study careful the the thread posted here by ytKARL:http://productforums.google.com/forum/#!category-topic/youtube/watching-videos/H27ZwguSN2kIn particular -study what Adobe has to say on the issue. The link is here:http://forums.adobe.com/thread/1018071?tstart=0And if you have trouble viewing the "How to fix it video" on the Adobe website,the same video is here on YouTube:http://www.youtube.com/watch?v=oQbu0k0rPwc&feature=player_embeddedAlthough this trouble is reported to have started with Firefox 13 + Adobe Flash 11.3.300.257It could still affect a newer version of Flash - which you already have.So please study in detail the given links and follow the recommended fixes.If none of those help, then please provide more technical details regarding your browser and version, what addons you have installed to Firefox,and your GEO location ( country/state)Also - if the resources DO help relsolve it for you, then please provide exactly what resolved it for you. That information in return will likely help others with the same issue.Regards,Klementine |