Over night our installation of MOSS seemed to have stopped working. For ever user it is asking for credentials. You log in with the credentials and then you get the Access Denied error. This is happening for everyone. Any ideas what could be wrong?
I have the same problem. No one but Site collection administrator could login.
My problem was that my masterpage has not been approved.
This article helped me to start with the troubleshooting.
I dont remember, but I think that:
Also you can check user permissions on MOSS site-collection:
http://MOSS/_layouts/user.aspx - does you have Domain Users or Authenticated users read permissions there? In default configuration all MOSS permissions inherited from that place.