Inconsistent URL behavior

[cognosfreelancer]

I have single signon enabled with my Active Directory Provider ( yes it works).

When I access the portal with the following URL 'http://servername/crn' I get logged in automatically.

When I attempt to access the portal by entering 'http://servername/crn/cgi-bin/cognos.cgi' I get prompted to enter my network user id and password.

This is weird as the first URL resolves to the second URL after a successful login.

Moreover Web server and NTFS file permissions are consistent.

Why then does one URL behave differently from the other. :o

NKT