Exchange 2010 install error

I know its more that I'm tired than anything else, but I need help solving this issue.  I'm installing Exchange 2010 on Windows 2008 where the PDC is a Windows 2003 server.  Another 2008 server exists in the the same domain...but I'm pretty certain that doesn't matter.
The error is below (installing mailbox role).  Can someone help me through this please?
BTW, as with every other error, Microsofts help has been ....grrr....responded with this message:
"You've found an error that doesn't have an article written about it."  

The error...

Mailbox Role
Failed
Error:
The following error was generated when "$error.Clear();
          $name = [Microsoft.Exchange.Management.RecipientTasks.EnableMailbox]::DiscoveryMailboxUniqueName;
          $dispname = [Microsoft.Exchange.Management.RecipientTasks.EnableMailbox]::DiscoveryMailboxDisplayName;
          $dismbx = get-mailbox -Filter {name -eq $name} -IgnoreDefaultScope -resultSize 1;
          if( $dismbx -ne $null)
          {
            $srvname = $dismbx.ServerName;
            if( $dismbx.Database -ne $null -and $RoleFqdnOrName -like "$srvname.*" )
            {
              Write-ExchangeSetupLog -info "Setup DiscoverySearchMailbox Permission.";
              $mountedMdb = get-mailboxdatabase $dismbx.Database -status | where { $_.Mounted -eq $true };
              if( $mountedMdb -eq $null )
              {
                Write-ExchangeSetupLog -info "Mounting database before stamp DiscoverySearchMailbox Permission...";
                mount-database $dismbx.Database;
              }

              $mountedMdb = get-mailboxdatabase $dismbx.Database -status | where { $_.Mounted -eq $true };
              if( $mountedMdb -ne $null )
              {
                $dmRoleGroupGuid = [Microsoft.Exchange.Data.Directory.Management.RoleGroup]::DiscoveryManagementWkGuid;
                $dmRoleGroup = Get-RoleGroup -Identity $dmRoleGroupGuid -DomainController $RoleDomainController -ErrorAction:SilentlyContinue;
                if( $dmRoleGroup -ne $null )
                {
                  Add-MailboxPermission $dismbx -User $dmRoleGroup.Identity -AccessRights FullAccess -DomainController $RoleDomainController -WarningAction SilentlyContinue;
                }
              }
            }
          }
        " was run: "Couldn't resolve the user or group "MY-DOMAIN-NAME-HERE.com/Microsoft Exchange Security Groups/Discovery Management." If the user or group is a foreign forest principal, you must have either a two-way trust or an outgoing trust.".

Couldn't resolve the user or group "MY-DOMAIN-NAME-HERE.com/Microsoft Exchange Security Groups/Discovery Management." If the user or group is a foreign forest principal, you must have either a two-way trust or an outgoing trust.

The trust relationship between the primary domain and the trusted domain failed.

Click here for help... http://technet.microsoft.com/en-US/library/ms.exch.err.default(EXCHG.141).aspx?v=14.1.218.11&e=ms.exch.err.Ex88D115&l=0&cl=cp

Elapsed Time: 00:00:04

Finalizing Setup
Cancelled