Using Firefox 3 with Scrum Dashboard and Team System Web Access is not a pleasant experience because Integrated Authentication is by default disabled resulting in login dialogs every time you fire up a new browser. You could use the IE Tab plug-in on a Windows box but another alternative is to actually enable Integrated Authentication.

How-to:

1. Write about:config in the toolbar in Firefox and hit Enter

2. Write network.negotiate-auth.trusted-uris in the Filter text area

3. Edit this setting and set the value to http://TFSSERVER

4. Write network.automatic-ntlm-auth.trusted-uris in the Filter text area

5. Edit this setting also and set the value to http://TFSSERVER

6. Restart Firefox

Note! Replace TFSSERVER with the name of your TFS-server.

Reference: http://www.mozilla.org/projects/netlib/integrated-auth.html