BUG #7760: records with duplicate primary keys

The following bug has been logged on the website:

Bug reference:      7760
Logged by:          Alan Cummings
Email address:      acummings@aperiogroup.com
PostgreSQL version: 9.1.7
Operating system:   Ubuntu Linux 10.04.1
Description:        =


We found 6 duplicated primary keys in a table. All fields were identical in
the duplicated records, including the primary key. (Total records ~ 22,000).
We recently updated from 9.1.2 to 9.1.7, so the issue may have been present
in 9.1.2. =


We have fixed the issue in our table by backing up the table in pgAdmin to a
plain file, deleting the duplicated records in the text file, then restoring
the table.

I can send the original backup with the duplicated records if that would be
helpful -- it is about 11MB.