Do you have the problem from QV Server or Desktop? Wich database?
If you tested the connection from QV desktop and it fails in QV Server probably is because you are using a diferent user.
What kind of access he you talking about because I can interface the with the progress db seeing the the various tables and field in the ''Create Select Statement' window in QV desktop.
As long as I remenber, Postgres has a tool called 'DataAdministration'; but I'm not sure.
If I were you I would try to access from another tool If you have the same problem probly is a privileges problem.