Enterprise manager: ask credentials 2 times, now 403 Forbidden!?

[Yorix]

Hi, I installed the Enterprise Manager, and the first time I tried the website it asked for a credential. I entered my admin user, then the login page show up to login to the manager!
I login again and it worked. But now it don't ask for any credentials and only show :

403 - Forbidden: Access is denied.
You do not have permission to view this directory or page using the credentials that you supplied.

Does someone have an idea? I guess the problem come with the first credential which shouldn't be there, not sure what to check I'm not very good with IIS.
thank you

[Yorix]

Well it was the SSL Settings, I check "ignore" and now it work.