hello jeffmcintosh, can you try to [[Reset Firefox – easily fix most problems|refresh firefox]] and see if this addresses the issue?

Philip - tried that, nothing. Tabs are still frozen

Start Firefox in <u>[[Safe Mode|Safe Mode]]</u> to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem. *Switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance *Do NOT click the Reset button on the Safe Mode start window *https://support.mozilla.org/kb/Safe+Mode *https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes ---- There are other things that need your attention. Your System Details List shows multiple Flash plugins. * Shockwave Flash 16.0 r0 *Shockwave Flash 11.9 r900 You can find the installation path of all plugins on the <b>about:plugins</b> page. *http://kb.mozillazine.org/Issues_related_to_plugins#Identifying_installed_plugins You can check the Flash player installation folder for multiple Flash player plugins and remove older version(s) of the plugin (NPSWF32) and possibly (re)install the latest Flash player. *(32 bit Windows) C:\Windows\System32\Macromed\Flash\ *(64 bit Windows) C:\Windows\SysWOW64\Macromed\Flash\ You can uninstall the current Flash player version and (re)install the latest Flash version. See this about uninstalling Flash players: *http://helpx.adobe.com/flash-player/kb/uninstall-flash-player-windows.html Note that this will remove all installed Flash players. You can find the latest Flash player versions for Firefox on this page: *http://www.adobe.com/special/products/flashplayer/fp_distribution3.html