Many thanks paulae!!! Now work apparently correctly.
The activities that I make are:
Rewrite my .htaccess. (it not convinced me, i have create new file and rename old. content is the same for both)
i have remove the directory atahualpa351 previously loaded with ftp and installed new theme with the wordpress function.
Now Atahualpa 3.5.1 work
The first plugin problem is ozh-admin-drop-down-menu. With this plugin active, the layout of the page Atahualpa option is messy.
Now unfortunately I can not do other tests, my hosting service has problems with .htaccess file!!! Maybe all my problems are due to their
Many thanks at all for your support