login to console disabled

[ken]

We have two servers both running redhat.  On one of them it's possible
to log in (as superuser or user) via the console, but on the other it is
not (neither user nor superuser).  Both connect through an Avocent
console server to the serial ports.  Both have the same securetty file
with "console" at the top.  What do I need to change to allow console
login (to both user and superuser) in through the console?  (I looked at
a couple pam files, but they are identical also.

Thanks very much.

-- 
Everything's easy one you know how to do it.
   --Tulku Zlo