Any error messages in the Browser Console? *https://developer.mozilla.org/en/Tools/Browser_Console ---- You can check for sandbox security related issues. You can set this pref to 2 or 1 on the <b>about:config</b> page to lower the sandbox security setting. *security.sandbox.content.level = 1 *close and restart Firefox to make the change effective. If '1' still doesn't have effect then try '0' to disable the sandbox. If this didn't work then undo/reverse the change and reset the pref via the right-click context menu to the default value. You can open the <b>about:config</b> page via the location/address bar. You can accept the warning and click "I accept the risk!" to continue. *http://kb.mozillazine.org/about:config