can't access table properties in 1_1_20

When I try to access "properties" of a table, either via the
right-button menu or the toolbar button, I get an alert titled
"pgAdmin II Error" saying

    An error has occured in pgAdmin II:frmTable.Initialize:
        Number: 457
        Description: This key is already associated with an element of
        this collection.

A "Table" dialog window comes up, but it has no content in the various
fields.

This is happening with pgAdmin II version 1.1 build 20 on an NT 4 SP 6
machine, accessing a PostgreSQL 7.1.2 server hosted on an NT Cygwin
system.

I have used the older version of pgAdmin on this same database, and it
worked well -- no obvious problems.  There are pgadmin_* objects
(tables, functions, views) in the database left over from that older
pgadmin.  I tried removing all those objects, thinking that they might
be obsolete, but that made no difference.

--
Fred Yankowski           fred@OntoSys.com      tel: +1.630.879.1312
Principal Consultant     www.OntoSys.com       fax: +1.630.879.1370
OntoSys, Inc             38W242 Deerpath Rd, Batavia, IL 60510, USA