Hi,
following css also fixes gridview header
.grid-header
{
font-weight: bold;
font-family: Verdana;
font-size: 11px;
background-color: #7A9FCB;
text-decoration: underline;
color: #ffffff;
text-align: left;
position: relative;
top:expression(this.parentNode.parentNode.parentNode.scrollTop-2);
left:expression(this.parentNode.parentNode.parentNode.scrollLeft-1);
right:1px;
}
and place the following tag in your page head section
<meta http-equiv="X-UA-Compatible" content="IE=7" />