BUG #2121: Problem with backup and query

The following bug has been logged online:

Bug reference: 2121
Logged by: Alexis Cedeo Trujillo
Email address: acedeno(at)ceis(dot)cujae(dot)edu(dot)cu
PostgreSQL version: 8.0 & 8.1.1
Operating system: Windows
Description: Problem with backup and query
Details:

Hello,
We are research`students
By this, we would like to catch The Postgre SQL`technical advisors
attention about a problem occured while using this tool.
These are the facts: while executing a consult, looked as a many to many
relationship between two entities, it didn`t return the
Expected results. Forthermore it generated a bug.
However, after installed all the aditional modules delivred with the
PostgreSQL 8.0 for windows, the consult were functioning goodly but by
generating another problem statement due to the newly features installed:
the incorrect database restore or simply the inability to realize this basic
operation.
We notify that before the aditional features installation, there wasn`t the
database restore problem.
So what can we do to resolve the problem?
By expecting your response,
Thanks.

Alexis Cedeo Trujillo