Is it possible to restore objects past the tombstone lifetime?
It is not possible to restore objects using backups which exceed the tombstone lifetime. This is a limitation of Active Directory.
Quest does not provide support for problems that arise from improper modification of objects using ADSI Edit.
The following statement about ADSI Edit was taken directly from Microsoft:
Warning: If you use the ADSI Edit snap-in, the LDP utility, or any other LDAP version 3 client, and you incorrectly modify the attributes of Active Directory objects, you can cause serious problems. These problems may require you to reinstall Microsoft Windows 2000 Server, Microsoft Windows Server 2003, Microsoft Exchange 2000 Server, Microsoft Exchange Server 2003, or both Windows and Exchange. Microsoft cannot guarantee that problems that occur if you incorrectly modify Active Directory object attributes can be solved. Modify these attributes at your own risk.
To check the setting within the domain, open adsiedit.msc and check the "tombstoneLifetime" attribute of the object "cn=Directory Service,cn=Windows NT,cn=Services" in the Configuration partition. The default value can be modified, however this change will only be reflected for new backups going forward, it is not retroactive. If the value is <not set>, the default value is 60 days.
Microsoft's TechNet article "Determine the tombstone lifetime for the forest" - http://technet.microsoft.com/en-us/library/cc784932%28WS.10%29.aspx