by Ken Task.
Try the following query on your DB via the mdl_config_plugins table:
select * from `mdl_config_plugins` where `plugin` like "%ldap%"
If I recall correctly (version 1.9 site was one I had helped auth vs open directory on a MacOSX server), one had to set ID Number in the mappings to uidNumber to get Moodle's PHP talking to the open directory server.
'spirit of sharing', Ken
