Tiger server with NetInfo upgraded to Leopard: no way to connect with ServerAdmin

Hi, I upgraded my server and it seemed to go all smooth. I can log in on the console, etc. but when I try to launch ServerAdmin, it always tells me that there is no such server or that the username/password are wrong. My suspicion is, but I can't confirm that, that the upgrade scripts migrate the local NetInfo into the Local directory service domain, but that higher level NetInfo domains are not migrated, and that I may have some invalid/empty/nonfunctional OpenDirectory setup now. The question is, how can I get the server to behave enough that I can access ServerAdmin and WorkgroupManager, such that I can configure the server. Right now, I can log in, but I can't change anything in the configuration, and since I turned off mail before the upgrade, I can't even send or receive mail.. Any ideas of what's going on? I do have a disk image with the server's state before the upgrade, so all that information is available. I can, if need be, revert back to 10.4.11, or use that to migrate information to a new server install. The question is, how to migrate, if need be, without losing gigabytes of IMAP mail, etc. Any hints?