Problem with CSS

Hello

i try to add a drop down menù on my website. I use this tutorial http://cssmenumaker.com/blog/wordpress-3-drop-down-menu-tutorial and this version of menu http://cssmenumaker.com/builder/547174 but i have some problem.

If you look at my website estatemare.it you can look, and single post sidebar, that are some problem. Th sub menu is over the first menu? Why?