here are my settings under authentication settings
dotnetnuke authentication settings
enabled - check, use captcha - uncheck
windows live id settings - disabled
openid settings - disabled
active directory setting
enabled - check, hide login controls - check, synchronize role - check
provider - AdsiAuthenticationProvider, authentication type - Delegation
root domain - dc=usi
username - portal (its a domain user)
email domain - @usi.edu.ph
auto-login ip address - blank