Problem with Safari on the menu

Hello,
Thanks a lot for you beautyful theme !!

I would like just know, if there is the possibility to correct few problems that I have on Safari?
On my home page, I have the bloc n°4 going up.
And on every pages: the menu item jumps all over the place when you switch between areas on the site, but become ok when you refresh the pages.

you can see the result here : my web site

Let me know if I can do something.
Many thanks and I which you my best !

Strega