Quote Originally Posted by linFox View Post
You haven't actually linked to your favicon in the headers.

Firefox shows the icon by coincidence because if it doesn't find an explicit favicon reference, it looks for one at http://www.domain.com/favicon.ico.

<link rel="shortcut icon" href="/to/your/favicon.ico" />
That's not necessary. I don't use favicon references in my headers, and mine are displayed fine in every browser that supports them.