[GeoNetwork-users] geonetwork desktop

I have just installed version 2.0.0 of geonetwork desktop, with all default settings. I just installed this version and not the last one because I did not want to install jre 1.5, as I have some applications that work with 1.4.2.
I am having a problem that may come from not being yet used to geonetwork or not having well understood the guide and tutorials.
I thought I could select “Remote search” and after choosing some item from the categories list, I would get some metadata from the servers listed in the “server” list to the left of the portal web page.
But I obtain the following message instead:

The requested operation could not be performed.

empty Z59.50 query:

I would like to know if somebody could point me to some documentation I could read or perhaps explain what I am doing wrong.

Severino Fernandez
INTA
Departamento de Teledeteccion
Ctra. de Ajalvir Km 4
28850 Torrejon de Ardoz
Spain
email: fdezas@anonymised.com,severinofer@anonymised.com
Tel +34916487800, +34915206362