I've to protect my root site with custom login & password box, so I created a node with the two required pages, login and error and I've set Public Access on my home node as Role based protection:

Then I created the user which will be used for authentication:

Finally I created the macro as an .ascx custom control. The code is very simple:

The code works perfectly, it gets the user's credentials and do validation, but the redirect does not work and I stay on the login page. It seems that the auth cookie is not written. The web.config looks as follows:

I checked the file permission on the folders, the umbraco log, but apparently there are no issues. Any helps?