Solution for SSO in Firefox!
I just figured out how to fix the SSO issue in Firefox. It turns out it's not a limitation of SSO, Tomcat, or SDP in general, but rather an advanced security setting in Firefox.
Normally when SSO is enabled and you go to your SDP site in Firefox, a login dialog box will appear requiring your domain username and password. This doesn't happen in IE as long as the site is in the local intranet zone, because NTLM pass-through authentication (a.k.a. single sign-on, or SSO) is allowed in that zone. Firefox does not have easily-configurable security zones, but there is an advanced setting in the prefs.js file that will enable this feature. This setting is per user (non-global), meaning if multiple people use Firefox under different logins on the same PC, these steps will have to be repeated for each one of them. Here's how to do it:
[list=1:0b38277039] * In Firefox, type about:config in the address bar to bring up the advanced preferences for Firefox
* Locate the preference labeled network.automatic-ntlm-auth.trusted-uris
* Double-click the blank value field and enter the address for your SDP server, as well as any other website addresses (optional) you want to enable SSO for, each separated by a comma, like so:
http://mysdpserver.mydomain.local,http://additional.website.com,http://yetanother.site.net
* Log out of SDP and close and restart Firefox
From now on, you should no longer receive a login dialog in Firefox for your SDP server or any other sites you entered. FYI, I have tested this on Firefox 2.0.0.13 and 3.0 beta 4. AdventNet, you probably want to add this to your knowledgebase, as well as the admin guide for SDP.