在 IE10 中 position:absolute 时不透明度不起作用

Opacity is not working when position:absolute in IE10

绝对位置时不透明度不起作用

a.Button5{
  display:block; 
  opacity:0.7;
  -webkit-transition: all 0.4s ease-in-out;
  -moz-transition: all 0.4s ease-in-out;
  -o-transition: all 0.4s ease-in-out;
  -ms-transition: all 0.4s ease-in-out;
  transition: all 0.4s ease-in-out;
 }
a.Button5:hover{
  opacity:1;
}


<a href="(imageFile)" class="button5" rel="lightbox[imgBox]">
            <div class="ch-item cha_01">
                    <div class="ch-info" style="top:0px; left:30px;">
                    <h3>(Text)</h3>
                    </div>
        </div>
</a>



.cha_12{
position:relative;
float:left;
width:225px;
height:160px; 
top:0px;
left:0px;
background-image:url(images/cha_ra_04.png); }

这很管用。 但是

.cha_12{position:absolute;
float:left;
width:136px;
height:378px; 
top:316px;
left:814px;
background-image:url(images/cha_ra_12.png);}

这在 IE10 中不起作用。(Firefox,chrome 工作得很好) 我不知道我做错了什么。请帮助我

更具体

a .ch-item {
    opacity:0.7;
    -webkit-transition: all 0.4s ease-in-out;
    -moz-transition: all 0.4s ease-in-out;
    -o-transition: all 0.4s ease-in-out;
    -ms-transition: all 0.4s ease-in-out;
    transition: all 0.4s ease-in-out;
}
a:hover .ch-item {
    opacity:1;
}