BUG #2121: Problem with backup and query

The following bug has been logged online:

Bug reference:      2121
Logged by:          Alexis Cedeño Trujillo
Email address:      acedeno@ceis.cujae.edu.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 Cedeño Trujillo