I have a working winbind/samba/kerberos installation working on RHEL4 & 5 servers. I can successfully join the domain, login with domain users, and access the system just fine.

However, on any of my systems, after a while of being connected, if I do an ls-lrat on my home folder, instead of seeing my username or group name, I see the UID or GID number.

I have the idmap_backend option configured (using rid: instead of idmap_rid: because I kept getting warnings in the logs that idmap_rid has been deprecated) and the UIDs & GIDs are the same on every box.

If I run any command that contains the username of a user that lost its mapping, the user's mapping comes back so that an ls -lrat now shows the correct username and group. Any command that uses the username, like finger or a cd into the user's directory or anything.

I cannot seem to find anything about this anywhere else and was wondering if anyone else has seen this and what needs to be done to fix it. It makes it so that a user cannot sudo or access much of anything.

Any ideas? Thanks in advance.

I think you should lose the backend mapping and allow winbind to it (allow winbind to enumerate uid and guid). Unless you have OpenLDAP server and you use it services for backend mapping.