css-在背景图片链接下填充文本链接-为什么?

我无法删除此页中链接下的填充 http://www.yart.com.au/stackoverflow/test2.htm

你可以在这里看到我的问题 http://www.yart.com.au/stackoverflow/blue.png alt text http://www.yart.com.au/stackoverflow/blue.png

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>

<style type="text/css">

*
{
  padding:0;
  margin:0;
  font:15px arial;
}

div
{
  display:inline;
  height:18px;
  line-height:18px;
  background-color :blue;
}

.PageMove
{
  display:inline-block;
  background-image: url(http://www.yart.com.au/stackoverflow/page_move.gif);
  background-repeat:no-repeat;
  width:18px;
  height:18px;
  line-height:18px;
}


.Text
{
 background-color :red;
 display:inline;
 height:18px;
 line-height:18px;
}


</style>
</head>


<body>

<div><a href="#" class="PageMove"></a><a href="#" class="Text">18 pixels high</a></div>

</body>

</html>