HTML Navigation Hover - html

Question

This is my nav bar with a drop down menu below some. Book goes below Departments, I have a lot more but this is an example. When I hover over more options, it loses focus on the nav bar and shows the on hover discription for an image. how do i stop this?
<div class="NavBar">
<div align="center">
<ul>
<li>Home</li>
<li>Departments
<ul class="MiniNavBar">
<li>Books</li>
<li>Books</li>
<li>Books</li>
<li>Books</li>
</ul></li>
<li>Top Brands</li>
<li>Gallery</li>
<li>About Us</li>
</ul>
</div>
</div>
My CSS
.NavBar{
background-color: #C10000;
height: auto;
width: 430px;
border: thin solid #000000;
border-radius: 5px;
margin-top: 8px;
}
.MiniNavBar{
width: 97px;
}
.NavBar ul ul {
display: none;
}
.NavBar ul li:hover > ul {
display: block;
font-family: Calibri;
font-size: 10px;
}
.NavBar ul {
padding: 2px;
list-style: none;
position: relative;
display: inline-block;
font-family: Calibri;
font-size: 15px;
}
.NavBar ul li {
float: left;
}
.NavBar ul li:hover {
background-color: #C10000;
color: #FFDD00;
}
.NavBar ul li:hover a {
background-color: #000000;
color: #FFDD00;
}
.NavBar ul li a {
display: block;
padding: 10px 10px;
background-color: #C10000;
color: #FFDD00;
text-decoration: none;
}
.NavBar ul ul {
position: absolute;
}
.NavBar ul ul li {
float: none;
margin-top: 0px;
position: relative;
}
.NavBar ul ul li a {
padding: 15px 40px;
background-color: #C10000;
color: #FFFFFF;
}
.NavBar ul ul li a:hover {
background-color: #C10000;
color: #FFFFFF;
}
.NavBar ul ul ul {
position: absolute;
left: 100%;
top:0;
}