SMB with OpenLDAP Authentication

Greetings! I have recently setup our 10.5 Leopard file server. It's running AFP and users authenticate using an external OpenLDAP server. This works great. However, I'd like to be able to offer an SMB service for some of my users, but I am unable to make the authentication work. I remember reading somewhere that maybe some changes need to be made in the Samba config, but can't find what I was looking at. Does anyone have any ideas on how I can make this work? Thank you much!