ERROR: operator does not exist: - oid

PostgreSQL: 7.4.5
PgAdmin III 1.2.0 Beta 2 (Sep 24, 2004)

When viewing data via the grid, either by clicking the glasses or right 
mouse clicking and selecting view data, on a table that is built without 
OIDs, the following error message shows:

ERROR:  operator does not exist: - oid
HINT:  No operator matches the given name and argument type(s).  You may 
need to add explicit type casts

This error does not occur when executing a query to show data
This error does not occur using PostgreSQL 8.0 beta2