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.

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

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