以下代码在火狐下和IE7各DIV之间相差一个像素，（注：就是在“selfinner2_bottom_left_top”“selfinner2_bottom_left_middle”“selfinner2_bottom_left_bottom”之间上下没有完全连接上，导致显示出了背景颜色）十分不解，请各位大虾帮忙看看，哪里出错了？
/*CSS代码段*/
.selfinner2_bottom {
width:935px;
}
.selfinner2_bottom_left {
width:247px;
height:172px;
float:left;
}
.selfinner2_bottom_left_top {
width:247px;
margin-left:1px;
height:19px;
}
.selfinner2_bottom_left_middle {
width:247px;
height:152px;
background-image:url(../images/images/left_08.gif);
background-repeat:repeat-y;
margin-left:1px;
clear:both;
}
.selfinner2_bottom_left_bottom {
width:247px;
height:7px;
margin-bottom:9px;
margin-left:1px;
clear:both;
}
/*页面文件代码段*/
<div class="selfinner2_bottom">
<div class="selfinner2_bottom_left">
<div class="selfinner2_bottom_left_top"><img src="../images/images/index2_09.gif" /></div>
<div class="selfinner2_bottom_left_middle"></div>
<div class="selfinner2_bottom_left_bottom"><img src="../images/images/left_10.gif" /></div>
</div>
</div>
