Eclipse, meet Subversion, vice versa, and PLEASE play nice together
Oh well. I thought it was too much to ask to expect Eclipse to play nice with Subversion -- that pesky annoying habit of blindly copying subversion metadata files, leading to irritating "The resource is a duplicate of .svn/..." errors, one for each directory you have within Subversion project.
But this little blog posting saved my day. Finally. After all the useless other workarounds (*), including installing Subversion-compatibility plug-ins (which could be useful per se, just not able to suppress this svn annoyance).
(* - yes, there are other ways to actually get rid of this warning, but usually less elegant; also, there are a few suggestions that do not even resolve it);