I have a standard Login ASP.NET 2.0 control on a login Page, a LoginName and LoginStatus controls on the member's page.
once the user login successfully I am redirecting the user to Member.aspx page. The following is my machine configuration

Windows XP Pro Service Pack2
IIS 5.1
SQL Server 2000
visual Studio 2005
DISABLE ANONMYOUS ACCESS IN IIS
ENABLE WINDOWS AUTHENTICATION
...