Maybe something on this page will remind you of what you installed on your system or of the message you saw.'

• http://kb.mozillazine.org/Removing_unwanted_content_on_webpages

I am only familiar with Adblock Plus, and if you blocked it with that you could simply bring up the the web page then use Ctr+Shift+V to view the blockable items on the list, which would tell you if anything is blocked by ADP and you could see what filter blocked it. But ADP does not ask if you want to block something on it's own.

What you indicate is more like NoScript, parental controls, or a Firewall which I think are likely to ask you what you want to do.

Type about:config into the location bar, if the nasty message comes up, before dismissing the message, uncheck the box so you won't be harassed again. Then in the filter box type in -- webkinz

see if anything shows up related to an extension.

Also clear the cache and the cookies from sites that cause problems.

"Clear the Cache":

• Tools > Options > Advanced > Network > Offline Storage (Cache): "Clear Now"

"Remove Cookies" from sites causing problems:

• Tools > Options > Privacy > Cookies: "Show Cookies"

More:

• http://kb.mozillazine.org/Error_loading_websites

There are also other things that need your attention.

Your above posted system details show outdated plugin(s) with known security and stability risks that you should update.

• Shockwave Flash 10.1 r82

Please update Firefox to the latest version via "Help > Check for Updates or Help > About Firefox"