Users unabled to login

["T. Srinivasa Rao" <trao cstp umkc edu>]

 Hello.. In my linux (kernel 2.0.36) machine. general users
 are not able to login. The syslog entries are looking like this..
 --------------------------------------------------------------------------
 Feb 26 16:18:49 sagar PAM_pwdb[658]: FAILED LOGIN 1 FROM sagar FOR trao,
 Authentication failure
 Feb 26 16:18:50 sagar pam[658]: pam_get_user: no username obtained
 Feb 26 16:18:50 sagar PAM-securetty[658]: can not determine username for
 this service!
 Feb 26 16:18:50 sagar PAM-securetty[658]: FAILED LOGIN SESSION FROM sagar
 FOR (null), Error in service module
 Feb 26 16:18:50 sagar PAM_pwdb[658]: 1 authentication failure; (uid=0) ->
 trao for login service
 -------------------------------------------------------------------------
 
 In fact, when I installed  redhat linux 5.0 (kernel 2.0.33), there was no
 problem. But after XFreed86 package (I am not sure how it is related to
 PAM), this problem arised? I tried later with upgrading PAM also.. Still
 the problem persists.. Can somebody give a clue hwo to about sorting this?
 The entries in /etc/pam.d/login look like these...
 
 ------------------------------------------------------------------------
 auth       required    /lib/security/pam_securetty.so debug
 auth       required    /lib/security/pam_pwdb.so shadow nullok debug
 auth       required    /lib/security/pam_nologin.so debug
 account    required    /lib/security/pam_pwdb.so debug
 password   required    /lib/security/pam_cracklib.so debug
 password   required    /lib/security/pam_pwdb.so shadow nullok use_authtok
 debug
 session    required    /lib/security/pam_pwdb.so debug
 ----------------------------------------------------------------------
 
 Please send replies to trao@cstp.umkc.edu
 
 Thanks in advance..
 Bye
 T.Srinivasa Rao