I am experiencing some technical difficulty when trying to use AD Authentication across domains.  In our organization all user accounts are in DomainA.company.com while all of our servers are in DomainB.company.com.  These are both child domains of Company.com and trusts have been established.  This is a massive corporate infrastructure so no changes can be made on the domain side.  I am hoping there is a way to do this within DNN.  I have used other web applications and been able to specifiy the Server in which to Authenticate with.  (DC1.domainA.company.com instead of DC1.domainB.company.com) and that has worked for those applications.  However in DNN there is no place to tell it to use domainA.  Enabling Authentication in DNN only allows DomainB to login.(I have a test user account in DomainB)  So it works.  I just want to be able to force it manually to Authenticate against DomainA instead.    Perhaps there is a way to change the Provider? Any help would be greatly appreciated.

Windows Authentication? If select, Windows Authentication is enabled for this portal
Synchronize Role? If select, user's role will be synchronized with Windows Active Directory security group each time user logon
Provider Select Authentication provider for this portal
Authentication Type Select Authentication type for this portal (Delegation is recommenced)
Root Domain: Root Domain in format yourdomain.com or DC=yourdomain,DC=com. Leave this value blank if you want to obtain Active Directory objects from root forest
User Name: User Name, who has permission to access Active Directory
Password: Password of this User
Confirm Password: Confirm Password
Email Domain: Email Domain to be used for user email when your network doesn't have Windows Active Directory (Blank is recommenced)

Yes, blank has the same result. 

If I use a blank Root Domain it passes but still points to DomainB.

If I use the parent domain as the root domain it points to DomainB

If I use a username and password from DomainA it fails.

If I use a username and password from DomainB it passes, but still only gives me access to DomainB.

It appears that it is not able to pass the request on to DomainA even though a trust is established and I can log into the web server using a user from either domain.  Using another CMS such as e107 or joomla I am able to specify the ldap or AD server in which to authenticate against.  I can point them to DomainA and all is well.  No such setting in DNN.  Is there a way inside the code to specify the server in which I autenticate or something other than AdsiAuthenticationProvider......