Facebook Like button causing error in Firefox

I'm try开发者_高级运维ing to use the Facebook 'Like' button on my site, but I cannot get it to work properly in Firefox. Using Firebug I can see that I am getting the error 'FB.provide is not a function', but I have no idea how to fix this.

It also appears that when I refresh the page in IE there is only about a 50/50 chance of the 'Like' button loading without causing an error.

Any help here would be appriciated.

Thanks.

This happens if you add the Facebook script twice on the site (search for "all.js").

Source: https://stackoverflow.com/a/4084335/2440