I am currently trying to connect to my Novell LDAP in SSL using C#. At first, I have tried exactly the same operation with authentication = None and it works perfectly.
My domain name was of this form: LDAP://xxx.yyy.zzz.com:999/o=XYZ,c=ZYX and in my query I had AuthenticationType.None set.
Now, if I try the same with: LDAPS://xxx.yyy.zzz.com:636/o=XYZ,c=ZYX and in my query I had AuthenticationType.SecureSocketsLayer set. I have an error: Unknown error (0x80005000) whereas the SSL is working on the server.
If you can get access to the eDirectory servers logs and ask them to enable +LDAP tracing, then a bind attempt that fails could provide additional interesting information.
As Joachim notes in his comment, you probably need the trusted root of the CA that signed the certificate in use by the eDirectory server. By default, each eDirectory tree has its own CA that signs all the certificates, so probably need the public key of the CA added to your keystore for certain.