Windows SBS 2003 administrator password breaker

I have a windows 2003 Small business server (which means it is a domain controller), administrator user cannot login, it gives the error that "the system could not log you on.  Make sure your username and domain are correct ......"  Same error for remote desktop attempts.

I have used a few password breakers to try to reset the administrator account, but I keep getting the same login error message, even though the password breakers finish normally.  I have used these breakers before with non-domain servers and have had good luck.

This is why I think it is a password issue, the administrator was logged in at the console and the screen saver comes on as usual.  You could log in again using ctrl-alt-del and the "known" password to get past the screen saver password.  I tried to access the server remotely to check why the backups had been failing, but I could not login.  In hindsight, I think the backups stopped because the password had been changed and the reason the local console could login was because it was the cached screen saver password.

When I rebooted the server to try to clear the issue, it no longer would let me login, locally or remotely.  Again in hindsight, had I known that the password was changed, I would have changed it before rebooting the server.  I don't know how the password could get changed but I believe it was done through remote desktop since the screen saver locally was still the "known" password.  It may be a hack and I am looking at the router logs to determine that.  The server runs fine and shares files and everything else it is suppose to do.

Can anyone suggest how I can get into the server as the administrator with a password breaker that works on domain controllers?  I don't have another user that is an administrator.

Thanks