Thanks for the quick reply!
My settings currently are:
Host URL: ldap://IP/
Bind User Distinguised Name: cn=moodle,OU=Users,OU=YYY,OU=INTERNAL
and contexts are set as per your reply.
(where IP is the IP address of the root server, YYY is the domain)
I created the user moodle in active directory (behind all the RM stuff) - do I need to set up anything for this user except for the password?
The error I get is:
LDAP-module cannot connect to any servers: Server: 'ldap://IP/' Connection: 'Resource id #51' Bind result: ''
Thanks again!