owners can not issue who command

["Sujit Choudhury" <S . Choudhury @ westminster . ac . uk>]

some of our list owners can not see who the members are.  They are 
issuing the following command:

>>>> who ncs-staff
**** List 'a-list' is a private list.
**** Only members of the list can do a 'who'.
**** You [ owner ] aren't a member of list 'a-list'.

Sujit Choudhury
University of Westminster.
London, UK.