It Can't Load Anti-Phishing On My Firefox Toolbar

Whenever Firefox opens, I get a Norton error message saying that the Anti-phishing application can't be loaded to the toolbar with the version of Firefox I'm using, and that I must upgrade to the newest version. It's been saying this for the past year now, even though I upgrade Firefox whenever it's available. I just upgraded again yesterday to the newest Firefox, and Norton still says it can't load the anti-phishing with "this version", and that I must upgrade to a newer version... which doesn't exist. Help?