Show the image tag for the favico.ico icon and indicate the jboss version.
I'm using jboss-3.2.1/tomcat 4.1.24. I don't have an image tag for the favicon.ico.
I wasn't planning on adding a favicon.ico (so didn't have the tag) and got the 404. To try and remedy that, I added a favicon.ico in / and then jboss/tomcat found the favicon.ico, but my browser loaded it as if it was redirected to the .ico file instead of a web page.
I had a similar situation when I tried to include a CSS in my login.html form login page -- after authenticating, rather than getting the protected page, I got the CSS loaded in the browser as a text file.
Some more information...
After the initial login and getting the 404, if I logout and log back in, I am correctly redirected to the protected page. This appears to happen after the initial deployment only.
I also tried two other browsers (Safari and Camino) and didn't see the problem (although Camino doesn't support favicons) -- so this happens with Mozilla Firefox.
I tried 3 different scenarios (w/Mozilla):
1) No html link for favicon.ico and no favicon.ico file present:
After the 1st login, I get a 404 for favicon.ico.
Subsequent logins work correctly until redeployment, where I get another 404 for the first login after deployment.
2) favicon.ico in / with no link
After the 1st login, I get a "Save To.../Open with..." dialog box for favicon.ico.
Subsequent logins work correctly.
3) favicon.ico in / with link (pointing to /favicon.ico)
Same results as #2.
If it's not already obvious, I'm using OS X...as the server and client.