This is the inverse of every favicon question you've ever heard. :-)
I've got my favicon working on all pages and across all browsers, save 1 situation. The icon doesn't show up in Firefox and Google Chrome on my sign in page -- https://fwdvault.com/signin
IE, Opera, and Safari pick it up just fine.
The logic that builds the header is the same for this page as all the others, no code differences.
Compare with any other page on the site -- fwdvault.com
Any ideas? I'm totally stumped.