backup remote domain system state w/o trust

[rpcblast]

Ok here is my situation
I have a DMZ if you wanna call it that with a seperate AD, 3 servers total, for a web/ecommerce site.  The only thing I NEED to backup is the database, but would like to backup AD as well, since the computer account info is being used for sql authentication.  I installed the remote agent on the DC and sql box, set the network ports and opened ports 10000 and the other needed ones in my firewall(inside to DMZ only).  Now, it backs up sql just fine, but will not backup the system state, gives me an access denied error.  On the DC, the remote agent is running as local system, and the account I put into backup exec as the account to use for this resource is the domain admin for the remote domain in the DMZ. 

Why will this not work?  I cannot create a trust as that would simply defeat the purpose of the seperation.  If the BE remote is running as localsys, and BE has the Domain admin account for the remote system, why is this failing? 
This backup exec instance is also responsible for my internal network backups, and as such the internal domain admin account is being used as the "system account" inside backup exec.  Also this is backup exec 2010

[sksujeet]

Make sure the account that you are using should have logon as batch in domain security policy.

Are you not able to backup anything on that server of just the system state. Have you tried backing up the other drives of that server. Please try if not tried

[rpcblast]

same error.  This is only happening when i try to backup the remote domain.  And the sql server on the same remote domain isbeing backed up just fine, as well as the system state.  I have even tried making the remote agent run under the domain admin account instead of the local system, and still no dice.  It cna backup a folder on the DC, just not the system state.  It is able to backup the system state on the locla domain DCs

[AmolB]

The remote agent has be configured with local system account.

Create a new account in Backup Exec for the other domain as "domain\administrator" and then try to backup system state only.

[rpcblast]

I figured it out for anyone wondering.  For some reason, it does not like the builtin domain admin account.  It could be that I changed the login name(but didnt rename the account itself).  Anywho, I created a new domain admin account and told the BE server to use that account, and it works fine.