If you see errors like :

Could not read attribute : CN=some-object-name\0aDEL:7dafdas3-23d-23c-8023-123212,ou=stoneware,dc=company,dc=com

Basically, the object is in a state of deletion and may be stuck due to bad replication or a server being down. 

Reanimating Active Directory Tombstone Objects

http://technet.microsoft.com/en-us/magazine/2007.09.tombstones.aspx