su hangs for 30 seconds

[Wolfgang S. Rupprecht]

As of a day or so ago "su" has started hanging for 30 seconds.  So has
the lock screen.  Jiggling the mouse unblanks the monitor and shows me
the backdrop picture but the password entry box doesn't appear for 30
seconds.  I don't believe I mucked with anything PAM related, but there
were a few yum updates in the last few days.  Is anyone else seeing
this?

-wolfgang
-- 
Wolfgang S. Rupprecht
If the airwaves belong to the public why does the public only get 3
non-overlapping WIFI channels?