Thanks Klap-in, I solved in this way:
Uninstalled /lib/tpl/dokuwiki with ftp
installed again (recovered correctness icons)
installed new copy style.local.ini (for my style)
logo.png installed in /lib/tpl/dokuwiki/images for my logo
installed copy of tpl.header.php in /lib/tpl/dokuwiki with customizing buttons
I'm really grateful.
http://www.ricercatoriliberi.org/doku.php?id=start
Thanks ach >>solved