Add back domain that has exceeded tombstone lifetime

http://technet.microsoft.com/en-us/library/cc949136(WS.10).aspx

Membership in Domain Admins, or equivalent, is the minimum required to complete this procedure. Review details about default group memberships at Active Directory Local and Domain Default Groups(http://go.microsoft.com/fwlink/?LinkID=150761).

Use Repadmin to restart replication following Event ID 2042

1. Open an elevated Command Prompt. To open an elevated Command Prompt window, click Start, point to All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator.
2. At the command prompt, type the following command, and then press ENTER:
   repadmin /regkey +allowDivergent

Reset the registry to protect against outdated replication

When you are satisfied that lingering objects have been removed and replication has occurred successfully from the source domain controller, use Repadmin to prevent divergent replication. To do prevent divergent replication, run the command repadmin /regkey -allowDivergent. For example, to restrict divergent replication on a domain controller named DC1 in the Fabrikam.com domain, run the command repadmin /regkey dc1.fabrikam.com –allowDivergent.