Have you noticed any problem with videos? https://support.mozilla.org/en-US/kb/fix-common-audio-and-video-issues https://support.mozilla.org/en-US/kb/troubleshoot-issues-with-plugins-fix-problems https://support.mozilla.org/en-US/kb/warning-unresponsive-plugin

Your system details list doesn't show the Shockwave Flash plugin as installed and enabled. *Firefox/Tools > Add-ons > Plugins You can find links of the latest Shockwave Flash player for Firefox on this page: * http://www.adobe.com/special/products/flashplayer/fp_distribution3.html You can verify on the Adobe Flash Players Test Page that the Flash plugin is working and which version you have. * http://www.adobe.com/software/flash/about/