Thanks to V. James Russ (Tennessee Valley Authority) and Peter Stern 
(Weizmann Institute) for responses.
The problem was my own fault.  When using Tiger-2.2.4 as a security 
checker, I became over-zealous and carried out the following recommendation 
in the Tiger output.
--WARN-- [permw] /etc/group should not have owner read.
--WARN-- [permw] /etc/group should not have group read.
--WARN-- [permw] /etc/group should not have world read.
--WARN-- [permw] /etc/passwd should not have owner read.
--WARN-- [permw] /etc/passwd should not have group read.
--WARN-- [permw] /etc/passwd should not have world read.
I changed the permissions, with the resulting odd behaviour of ls -l.  I 
have now changed them back to something less paranoid, and the problem has 
gone.
Cheers
Derek
_________________________
Derek Gatherer Ph.D. Cert.Ed.
Computer Officer
Institute of Virology
Church St.
Glasgow G11 5JR
Phone:      +44 141 330 6268
Fax:          +44 141 337 2236
Email:	      d.gatherer_at_vir.gla.ac.uk
Website:    
http://www.vir.gla.ac.uk
Received on Wed Oct 22 2003 - 09:36:22 NZDT