LDAP authentication for moregroupware?

hi there, i've just installed moregroupware according to the article here on afp548 (although I used it to install it on a machine running freebsd 5.1) however, i do want to use the ldap functionality of os x server for mgw to authenticate against. i'm running osx server 10.3.1 and am already using ldap for networked homedirectories, i.e. panther clients bind against [code:1:0098f40cfc]dc=domname,dc=tld[/code:1:0098f40cfc] successfully. when i enter this into the ldap setup screen of mgw, along with the admin name and passwort of the ldap domain i simply get thrown back after i submit the form. has anyone set this up already? perhaps i need to add something to the ldap base? any hint would be greatly appreciated, thanks, tom