I'm attempting to use the AD authentication provider, and it's giving me trouble when trying to authenticate against users in 2 separate AD Domains, i'm hoping someone can provide me with some guidance as to what I'm doing wrong.

I've got DNN 05.04.01installed and I'm attempting to utilize the AD Login provider. Within my AD structure I have a single forest with multiple trees (with a trust relationship established between both of them) Lets call them DOMAIN1 and DOMAIN2 respectively.
I have DNN running under an App pool with an identity in DOMAIN2.

The problem occurs when I try to authenticate. I've set up the a user in both domains with the same credentials to configure the provider to use. When I specify DOMAIN1\lookupUser it returns with the following under find all domains in network: "Could Not Access LDAP to obdain domains info" but otherwise completes successfully, and will authenticate users in DOMAIN1 but not DOMAIN2.

When I try DOMAIN2\lookupUser it fails completely claiming it can't find the user or bad password.

When I try just lookupUser without a domain specified it returns "1 Domain(s): DOMAIN2" however it will only authenticate users against DOMAIN1.

I need to be able to authenticate users in both domains, is there something I'm doing wrong here?