Menu Problem

Hello
I have problem about menu.
I put menu for my website but when put cursor on menu, 2nd menu not working.
I Have to scroll cursor for click 2nd menu

My website : http://shibuya-ortho.com

Maybe my English not good
please check problem by youtube link
http://www.youtube.com/watch?v=z7JPO0ydEyc&feature=youtu.be

my theme is Vantage premium.

thank you