Hello,

Please see the article How to fix preferences that won't save for information. Some files could just be locked, or a third party application, such as an antivirus, could be preventing your preferences from being saved.

Thank you for your rapid reply. Unfortunately, that was among the fixes I tried, and it didn't work. I even went so far as to deactivate my add-ons, reset Firefox and reinstall it. Nothing worked.

Note that your System Details List shows multiple Flash plugins.

• Shockwave Flash 11.3 r300
• Shockwave Flash 15.0 r0

You can find the installation path of all plugins on the about:plugins 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\

How do these network.proxy.* settings show on the about:config page?

• http://kb.mozillazine.org/network.proxy.type network.proxy.type

proxy.type  0:Direct  1:Man  2:Pac:ProxyAutoconfig  4:Auto-detect

• http://kb.mozillazine.org/network.proxy.%28protocol%29 network.proxy.http
• http://kb.mozillazine.org/network.proxy.%28protocol%29_port network.proxy.http_port