Menu Position Problem

I'm designing a webpage. You can see here : http://www.teknoblogo.com/yeni . There is a nav menu at top (ANASAYFA (home) , KATEGORİLER (categories), YAZAR HAKKINDA (about) ) .

There is a submenu on KATEGORİLER . But as you can see , submenus not bottom of KATEG开发者_开发百科ORİLER link.

Can you help me for solve this problem ?

Try to add position:relative to the parent <li> element and left:0 to the <ul> you're showing on hover:

style.css / line 234:

menu li {
    display: inline;
    margin-right: 5px;
    position: relative; // !
}

style.css / line 252:

#top-nav li ul {
    border-top: 1px solid white;
    left: 0; // !
    position: absolute;
    visibility: hidden;
}

Update 1 This is how it looks like in FF 3.6:

Update 2

style.css / line 260:

#top-nav li ul li {
   display: block;
}

style.css / line 252:

#top-nav li ul {
    border-top: 1px solid white;
    left: 0;
    top: 23px; /* You should play around with this value as you need it */
    position: absolute;
    visibility: hidden;
}