Decommissioned a file server, but every mobile account in the place is still trying to connect to it on login!

Question

A couple of months ago we decommissioned the 10.4.11 xserve that was serving as our LDAP server and home directory server for mobile accounts.  We migrated all of that to a newer 10.6.8 xserve.  It was a fairly rough migration, but we've pretty much sorted it out except for one last annoyance: when you look at System Preferences->Accounts->Login Items for all of our mobile accounts, every single client is still trying to mount an afp share on the old server.  Logging in takes FOREVER because the connection needs to time out, so now my users are no longer logging out/in as often as they should, and so their Home Sync's are getting old.
When you go to the client's Preferences, the line referencing the old server share is still there, but the minus sign is greyed out so the item cannot be deleted.
The Kind is listed as "unknown" and there is a grey warning triangle next to it.
This is clearly some sort of template/Preference that is hardcoded to the old name, and whatever file this is got moved to the new server (which has a different name and different numeric IP address.)  Because even the BRAND NEW users that I have created since after "pdc04.hgbc.com" disappeared are trying to log in to the non-existent share on the non-existent server, too!
I have tried running grep on the entire disk on one of the clients looking for the string "pdc04", and updated everything that I found using vi directly on the files.  I have tried running grep on select directory trees on the new file server looking for pdc04.  In my grep on the client, I found the string in
     /Library/Managed Preferences/user/loginwindow.plist
     /Library/Managed Preferences/user/complete.plist
but searching all of the logingwindow.plist and complete.plist files on the new server comes up with nothing.
Does anyone have any idea where the template or preference or plist is on the server so that I can delete or update the file with the new host name?

Answer 1

I think that Grant is on the right track -- but the problem is that whatever file that pdc04's Server Manager wrote into is not available to pdc's Server Manager to edit or even display.
We upgraded mostly by turning off the G5 10.4 xserve and unplugging the fiber-channel RAID (with user accounts on it) and plugging the RAID into a fiber-channel card on the new (to us) Nehalem 10.6 xserve, which we did after using Migration Assistant between the machines.  Then we had various and sundry problems, and we ended up moving all of the mobile account directories to the internal RAID on the new server.
Clearly there is a file somewhere that acts as a template for mobile accounts and it refers to the old machine but its been moved to the new machine.
Only two of the mobile accounts have directories in the /Library/Managed Preferences folder.  One of them, ironically, is mine, and my account hasn't worked right since we went to the new server.