I can not synchronize FDS with ADs
IN ADs I get this error:

12/15/08 11:59:33: PassSync service stopped
12/15/08 11:59:34: PassSync service started
12/15/08 11:59:34: Failed to load entries from file
12/15/08 11:59:34: LDAP bind error in Connect
81: Can not contact LDAP server
12/15/08 11:59:34: Can not connect to ldap server in SyncPasswords
12/15/08 11:59:34: Password list is empty. Waiting for passhook event

and In FDS I get this error:
LDAP error: Can not contact LDAP server.error code: 81

you can help me Plz