I found my error.
I wrote:
> Now I downloaded the new postgresql version (7.0.3) and installed it in
the > same directories where suse installed (/usr/lib/pgsql).
After this point, I made a terrible mystake. I changed the home directory
of user postgres from /usr/lib/pgsql to /usr/local/pgsql.
This directory was not in my hd, and, the error message was displayed.
Thanks for the help.