Alejandro,
> When I try to do a "select version();" or a "select 4 + 4;" or even a
> "select * from anytable;" I only receive a SELECT as response, what do you
> thing I'm doing wrong??
You've probably set your PSQL to output its results to a file. Try typing:
\o
to reset the response to the console.
--
Josh Berkus
Aglio Database Solutions
San Francisco