DRS replication unsuccessful?

[titantoppler at gmail.com]

Hello all,

I have 3 servers, called dc1, dc2 and dns1.

dc1 is the original DC, and dc2 and dns1 are joined to the domain as DCs.

samba-tool drs showrepl on dc2 shows:
---
*** some output snipped ***
CN=Configuration,DC=test,DC=local
        Default-First-Site-Name\DC1 via RPC
                DSA object GUID: 69ef47eb-59b7-4768-b806-d4abd794bb2b
                Last attempt @ Mon Jul  2 16:09:43 2012 SGT was successful
                0 consecutive failure(s).
                Last success @ Mon Jul  2 16:09:43 2012 SGT
CN=Configuration,DC=test,DC=local
        Default-First-Site-Name\DNS1 via RPC
                DSA object GUID: ddb57325-92b0-4ac6-bf50-7335185ee0d5
                Last attempt @ Mon Jul  2 16:09:43 2012 SGT failed, result
2 (WERR_BADFILE)
                3847 consecutive failure(s).
                Last success @ NTTIME(0)
*** some output has been snipped ***
==== KCC CONNECTION OBJECTS ====

Connection --
        Connection name: 0cfde227-79d6-42aa-ad1d-03ae99c05a5a
        Enabled        : TRUE
        Server DNS name : DC2.test.local
        Server DN name  : CN=NTDS
Settings,CN=DRAY-DNS1,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=test,DC=local
                TransportType: RPC
                options: 0x00000001
Warning: No NC replicated for Connection!
Connection --
        Connection name: 5489e53a-a708-4d5c-9b36-617be64c047e
        Enabled        : TRUE
        Server DNS name : DC2.test.local
        Server DN name  : CN=NTDS
Settings,CN=DC1,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=test,DC=local
                TransportType: RPC
                options: 0x00000001
Warning: No NC replicated for Connection!
---

Notice that dc2 and dns1 are not replicating to each other, though dc1 and
dc2 are fine, as is the replication between dc1 and dns1.

What could be the problem here?

Cheers!