CSS hover firing more than once with webkit 3d transform

When I use a webkit 3d transform on hover, only the top 50% of the hover area works, while the bottom 50% is unstable. I'm currently testing on Chrome (31.0.1650.63). Is it a bug? Is there any workaround?

Try to place your mouse on the top of the div and slowly bring it to the bottom.

HTML

<div class="hoverArea"></div>
<div class="flip">
    <div class="front">front</div>
    <div class="back">back</div>
</div>

CSS

.hoverArea, .flip, .front, .back {
  width: 200px;
  height: 200px;
  position: absolute;
  top: 0;
  left: 0;
}
.hoverArea {
  z-index: 10;
}
.flip {
  -webkit-transform-style: preserve-3d;
  -webkit-transition: 0.5s;
  -webkit-perspective: 800;
  z-index: 9;
}
.front {
  background-color: #f00;
  -webkit-backface-visibility: hidden ;
}
.back {
  background-color: #f0f;
  -webkit-transform: rotatex(-180deg);
  -webkit-backface-visibility: hidden ;
}
.hoverArea:hover + .flip {
  -webkit-transform: rotatex(-180deg);  
}

http://jsfiddle.net/4P53y/

You can fix it by removing the .hoverArea element and instead apply the :hover event on the .flip element.

.flip:hover {
    -webkit-transform: rotatex(-180deg);    
}

Demo

If you want to still use the .hoverArea element then you can use transform:translateZ(1px); on .hoverArea to make it function correctly. It makes the browser render the element more carefully

.hoverArea {
    z-index: 10;
    -webkit-transform:translateZ(1px);
}

Demo