Trouble with SMB and Active Directory logins

We are having an issue where after SMB magically stopped working on Snow Leopard again, we tried going ahead with the Lion update, only to find that it has the same issue. Nothing can connect to the Lion server using AD accounts via SMB. Local accounts work via SMB. AD accounts can connect via WEBDAV and AFP. I thought that this would be resolved with Lion. I really don't know what their aversion to using the mainline Samba is. I have several Redhat servers that server SMB perfectly fine to AD accounts. If it wasn't for creator code issues, I would migrate all the data off of this server and shut it down for good.