su operation on RHES V5.2

[Licause, Al]

A few days ago, I sent an e-mail regarding the behaviour of
su - username    as seen in Redhat enterprise edition v5 update 2.

Briefly if you su - username and that user name is an ldap user,
no action appears to be taken.   The log shows the user was accessed
then immediately disconnected.

We have since found that if the nscd daemon is running, the su - username
command works for ldap users.     But as soon as nscd is stopped, the command
again fails to take any action.

We also reported that if su is run with strace, the command also succeeds.

Can you tell us if this is expected behaviour ?

Al Licause
HP Services
Unix Network Team