Active Directory vs normal sign-up users in kayako

Hi there.

We installed and configure LDAP AD authentication for users and it works well.
But since we did that, the normal sign up users can not login. Although new users can register but when they try to login they get "Invalid User and Password".
How we can have AD login and normal user login alongside?
We have to have both login strategy.
# We use this
http://forge.kayako.com/projects/ad-ldap-authenticator
for setup and configure.

Thanks for any helps.