We use FormAuthentication to manage logins and I have a case where a customer complains where he can login from one computer but to from another.
I can see in my logs that his authentican is successfull but he gets bumped back to the login page. I can reproduce the symptons by disabling cookies so I asked the customer to test if cookies are enabled on http://www.tempesttech.com/cookies/cookietest1.asp, but this came out positive.
What have I missed? Is there any antivirus/security software that can mess up (ASP.NET) cookies?
The user is using IE7 and claims to have F-secure installed.