home dir unmounting problem

I have just set up a Tiger server on a dual G4 (mirrored doors). Two disks are connected to the ATA100 bus and the system is installed in a mirrored partition on those disks. A seritek card is driving two 400Gb mirrored drives to host the home directories (/homes). All disks were formatted with SoftRaid 3.2. Only the admin user is local to the server which is set up as an Open Directory Master (LDAP).
I set up the sharing point for the /homes, enabled quotas and set up automount. I then set up the users and groups and a group folder. When logging in from a remote client everything works fine. I can login and logout as any network user and I can connect several users to the server with no problem. However, if I login as a network user directly on the server console (that is on the dual G4 mirrored doors) everything works OK the first time but when I logout and log back in, the /homes are not visible anymore and all the clients loose the connection to the share point. It seems that as soon as a network user sitting at the server logs out, the /homes disk is unmounted and cannot be mounted again.
I am totally new to server set up and admin. What I need is a very simple set up for my lab computers. Am I doing something stupid here?

I have posted this to the Apple Macos-x-server list and at least one other person has the same problem but we did not get any solutions.

Any hep is greatly appreciated.