First:

I wrote about this kind of error to Google Earth Support last year, but it seems to be not important for them.

Second:

The only official version for toponymia in Catalonia is the published in the Catalan Government databases, following the regulations of Decret 78/1991 which you may read in http://www.bibiloni.net/legislacio/decret_78.htm

And the list for the whole accepted toponyms is published in PDF and XLS formats in http://www10.gencat.net/ptop/AppJava/cat/documentacio/llengua/toponimia/nomenclator/index.jsp
(this is one of the pages in the Catalan Government's Planning, Territorial affairs and public works Ministry)

As you may suppose, the Catalan Government is part of the official spanish institutions and has exclussive attributions in the area of toponymia in the catalan territory.

Third:

Toponyms used in Google Earth are the ones used during the Franco era which substituted the official names at the same time that Catalan was forbidden and people who used Catalan suffered prosecution, so I think it's not only an error but an offending question for people in Catalonia. But now you may say I'm speaking about politics...

Fourth:

Some of the toponyms DO NOT EXIST, neither in Catalan nor in Castillian. I never heard about "Golfo de la Monedera"; it maybe refers to "Golf de la Morisca" which should be in Castillian "Golfo de la Morisca" . I don't understand why "Sierra de Matas" (this is a small hill) appears in screen but the whole "El Montnegre" does not appear (could you forget the Appalachian ?) - The same for "Sierra de las Concas". The same for big cities like L'Arbo� and El Vendrell which don't appear but some small or sometimes unpopulated towns do.

Fifth:

I'ld be glad and happy if some of the railroads drawn in the maps could exist today. Near Berga, because it should be a high speed railway straight from Barcelona to Paris (but the old and dissapeared train NEVER went straight through tunnels but in zig-zag at the side lane of the old car road). In the other cases, because it could tell they are not abbandoned. The problem lays in the moment ALL these raildroads dissapeared: this was during the 1960's.

Conclusion:
I think Google Earth is using the mistaken militar database written during the '40s (when "marchants" changed to "martians" and "abbandoned cabin for trash" was jerarchically over the names of towns and cities).
As topographical information is freely accessible in http://www.icc.cat (the official cartography department) I think there should not be more problems to correct Google Earth and, even, have for Catalonia the most perfect and complete map base and database in Google Earth.