I have been using Adobe since the Macromedia days and I find it difficult to believe that Adobe has yet to build in the capability to export image files as favicon.ico.
If you google it, you can see lots and lots of dated pages, with the last legit post from John Dunn ing (http://johndunning.com/fireworks/about/ExportAsFavicon). Really?
To boot, can you really trust some piece of code you need to download from a third party site?
I guess you can use CS5 Photoshop, but there is no reason why CS5 Fireworks shouldn’t be able to do it.
Rather than banging my head against the wall, just create a PNG image that is 16 x 16 pixels, then use this link (http://iconverticons.com/) to convert and download it.
Problem solved. Next!!