How do I get the Favicon on Favourites updated?

I've changed the favicon on one of my web sites.

The new one shows on the browser (FF 3.6.8) address bar and the tab. I can't get it to update on the Favourites menu. Any thought on how to do so?

Try deleting the favourite, shutting all IE windows, and then adding it again.

These favourite icon things are a bit of a mystery with IE - they tend to change "eventually" which is not very precise, suspect they're locally cached.

They've now changed, so it must be some time based activity. I did mention it was FF not IE, they're fine on IE