I am using LDAP authentication on my Ubuntu 11.10 server. I installed libpam-ldap, and configured things accordingly. It works great, except that I get this error every once in a while when I try to sudo:

sudo: setreuid(ROOT_UID, user_uid): Operation not permitted

I know I have sudoers set up correctly, since it works most of the time. It's not just my log in either, others have the same problem when I have it. When this error is occurring, I can't ssh in with my regular system user at all. When I sign in directly, I can't get any gnome-terminal to start.

Once I restart the server, the problem goes away. 'Course, that's not a solution, if it was a prod server, I'd be in trouble.

How do I fix this?

Edit 3/1/12: I just figured out that if stop and start the nscd service, the problem goes away.

service nscd stop
service nscd start

Not much of a solution since I have to be logged into the server directly, not via ssh.