Modify application partition object (root) in ADLDS

Question

I am not able to modify application partition (root object) in ADLDS instance.
In our directory we need one objectClass and its attributes in application partition (root) object.  When I try to add this objectClass (simple modify command) it is throwing an error (Code 65-ObjectClasss violation), the same class was added in old
directory (Sun ONE Directory Server).
The require objectClass and its attributes are available in ADLDS schema. Here are modify operation:
dn: O=Company.com
changetype: modify
add: objectClass
objectClass: xyzObjectClasss

Answer 1

adding to the above point..
I did some RnD and found that, we can add above OC(auxiliary) in root object if ADLDS instance is independent (no replication set with other instances or no replication kind of att in root object). I am not sure if this is creating issue here.
But we  unable to add when two instances on diff servers with replication mode.
*********Here is the dump of application partition where we failed
dn: O=Company.com
objectClass: organization
objectClass: top
instanceType: 5
O=Company.com
objectCategory: CN=Organization,CN=Schema,CN=Configuration,CN={123xxxxxx1231xxxx}
distinguishedName: O=Company.com
dSASignature:: asdsdasdfsfsdfksjdflksfsdfklsdklsdmklsdmvsdlv==
dSCorePropagationData: 16010101000000.0Z
msDs-masteredBy: CN=NTDS Settings,CN=xxxxxxxxxxxxxxx$Instance2,CN=Servers,CN=
 Default-First-Site-Name,CN=Sites,CN=Configuration,CN={123xxxxxx1231xxxx}
msDs-masteredBy: CN=NTDS Settings,CN=xxxxxxxxxxxxxxx$Instance1,CN=Servers,CN=
 Default-First-Site-Name,CN=Sites,CN=Configuration,CN={123xxxxxx1231xxxx}
name: Company.com
objectGUID:: neaeNZEE/kWGbDxPDhky6w==
replUpToDateVector:: axaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxaxAgAAAAAAAAABAAAAAAAAACtjikq6OHJNjHrspgmOZXxFWQ4AAAAAABS
repsFrom:: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx==
repsTo:: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx==
uSNChanged: 927798
uSNCreated: 8198
wellKnownObjects: B:32:A9D1CA15768811D1ADED00C04FD8D5CD:CN=Roles,O=Company.com
wellKnownObjects: B:32:6227F0AF1FC2410D8E3BB10615BB5B0F:CN=NTDS Quotas,O=Company.com
wellKnownObjects: B:32:AB8153B7768811D1ADED00C04FD8D5CD:CN=LostAndFound,O=Company.com
wellKnownObjects: B:32:18E2EA80684F11D2B9AA00C04F79F805:CN=Deleted Objects,O=Company.com
whenChanged: 20140702003049.0Z
whenCreated: 20130123142544.0Z
createTimeStamp: 20130123142544.0Z
modifyTimeStamp: 20140702003049.0Z
structuralObjectClass: top
structuralObjectClass: organization
subSchemaSubEntry: CN=Aggregate,CN=Schema,CN=Configuration,CN={123xxxxxx1231xxxx}
Thanks