Thread:Extension talk:LDAP Authentication/LDAP auth works, but cannot get SSO to work

This problem has been driving me insane. (Note: all versions and settings are below) I have mediawiki setup with the LDAP Authentication plugin. I have it successfully authenticate against AD, it will filter by group without any trouble, and it will even import nickname, realname, and email addresses without any issues. I add the appropriate settings to turn on SSO (and take out the one line I don't need) and then all I get is HTTP 500 errors. I have gone through an unbelieveable amount of documentation on this and found nothing. Other plugins can do SSO, but they can't do the group based filtering that this one can. I need some help understanding what is going wrong.

OS: Windows Server 2008 R2 SP1

Webserver: IIS 7.5 (I have to use this; Apache is not an option.)

Mediawiki Version: 1.20.2

LDAP Authentication Version: 2.0c

PHP Version: 5.3.21

MySQL Version: 5.5

LDAP Directory: Active Directory on Server 2008 R2 running at Server 2003 Level

Web Site Authentication Settings:

Anonymous Authentication: Disabled

Basic Authentication: Enabled

Windows Authentication: Enabled

Here are the added lines to my localsettings.php:

require_once("$IP/extensions/LdapAuthentication/LdapAuthentication.php");

$wgAuth = new LdapAuthenticationPlugin;

$wgLDAPDomainNames = array( "CPHOSPITAL" );

$wgLDAPBaseDNs = array( "CPHOSPITAL"=>"dc=cphospital,dc=org" );

$wgLDAPServerNames = array( "CPHOSPITAL" => "CPH-SRV-DC1 CPH-SRV-DC2" );

$wgLDAPSearchStrings = array( "CPHOSPITAL" => "USER-NAME@CPHOSPITAL.ORG" );

$wgLDAPEncryptionType = array( "CPHOSPITAL" => "clear" );

$wgLDAPRetrievePrefs = array( 'CPHOSPITAL' => true );

$wgLDAPPreferences = array( "CPHOSPITAL"=>array( "email"=>"mail","realname"=>"cn","nickname"=>"sAMAccountName","language"=>"preferredLanguage") );

$wgLDAPRequiredGroups = array( "CPHOSPITAL"=>array("CN=Information Systems - Security,OU=Information Systems,OU=Departments,OU=Canton Potsdam Hospital,DC=cphospital,DC=org") );

$wgLDAPGroupUseFullDN = array( "CPHOSPITAL"=>true );

$wgLDAPGroupObjectclass = array( "CPHOSPITAL"=>"group" );

$wgLDAPGroupAttribute = array( "CPHOSPITAL"=>"member" );

$wgLDAPGroupSearchNestedGroups = array( "CPHOSPITAL"=>true );

$wgLDAPGroupNameAttribute = array( "CPHOSPITAL"=>"cn" );

$wgLDAPSearchAttributes = array( "CPHOSPITAL"=>"sAMAccountName" );

This setup works perfectly. Here is what I changed to turn on SSO:

require_once("$IP/extensions/LdapAuthentication/LdapAuthentication.php");

require_once("$IP/extensions/LdapAuthentication/LdapAutoAuthentication.php");

//$wgAuth = new LdapAuthenticationPlugin;

$wgLDAPAutoAuthDomain = "CPHOSPITAL";

$wgLDAPDomainNames = array( "CPHOSPITAL" );

$wgLDAPBaseDNs = array( "CPHOSPITAL"=>"dc=cphospital,dc=org" );

$wgLDAPServerNames = array( "CPHOSPITAL" => "CPH-SRV-DC1 CPH-SRV-DC2" );

$wgLDAPSearchStrings = array( "CPHOSPITAL" => "USER-NAME@CPHOSPITAL.ORG" );

$wgLDAPEncryptionType = array( "CPHOSPITAL" => "clear" );

$wgLDAPRetrievePrefs = array( 'CPHOSPITAL' => true );

$wgLDAPPreferences = array( "CPHOSPITAL"=>array( "email"=>"mail","realname"=>"cn","nickname"=>"sAMAccountName","language"=>"preferredLanguage") );

$wgLDAPRequiredGroups = array( "CPHOSPITAL"=>array("CN=Information Systems - Security,OU=Information Systems,OU=Departments,OU=Canton Potsdam Hospital,DC=cphospital,DC=org") );

$wgLDAPGroupUseFullDN = array( "CPHOSPITAL"=>true );

$wgLDAPGroupObjectclass = array( "CPHOSPITAL"=>"group" );

$wgLDAPGroupAttribute = array( "CPHOSPITAL"=>"member" );

$wgLDAPGroupSearchNestedGroups = array( "CPHOSPITAL"=>true );

$wgLDAPGroupNameAttribute = array( "CPHOSPITAL"=>"cn" );

$wgLDAPSearchAttributes = array( "CPHOSPITAL"=>"sAMAccountName" );

AutoAuthSetup;

After that, it will only give me HTTP 500 errors; it will not display the website. Have no idea what to do. Any help would be appreciated. Thanks.