hello together,
the google earth interface is a little bit buggy,
the kml which is generated uses the getcapabilities url to request. this url
is not defined to make a getmap request which google earth needs. either the
getmap url must be used directly - if given in the metadata 
(i don't think
it is always there) - or the capabilities must be parsed and the getmap url
must be extracted and copied into the kml-snippet.
regards
armin
--
Im Auftrag
--
Armin Retterath
Kompetenz- und Geschäftsstelle Geodateninfrastruktur Rheinland-Pfalz
beim
Landesamt für Vermessung und Geobasisinformation Rheinland-Pfalz
Ferdinand-Sauerbruch-Straße 15
56073 Koblenz
Telefon 0261/492-466
Telefax 0261/492-492
armin.retterath@anonymised.com
http://www.geoportal.rlp.de