Background-Image working in IE but not Firefox

[samv12]

Here's my css code:

/*GridViewCSS White Chrome Style*/
.GridViewStyle
{
    font-family: Arial, Sans-Serif;
    font-size:small;
    table-layout: auto;
    border-collapse: collapse;
    border:#999999 1px solid;
}
/*Header and Pager styles*/
.HeaderStyle, .PagerStyle 
{
    background-image: url('../Images/HeaderWhiteChrome.jpg');
    background-position:center;
    background-repeat:repeat-x;
    background-color:#fff;
	border-bottom:solid 1px #999;

    
}
.HeaderStyle th
{
    padding: 5px;
    color: #333;
    
}
.HeaderStyle a
{
    text-decoration:none;
    color:#333;
    display:block;
    text-align:left;
    font-weight:normal;
}
.PagerStyle table
{
    text-align:center;
    margin:auto;
}
.PagerStyle table td
{
    border:0px;
    padding:5px;
}
.PagerStyle td
{
    border-top: #999999 1px solid;
}
.PagerStyle a
{
    color:#333;
    text-decoration:none;
    padding:2px 10px 2px 10px;
    border-top:solid 1px #fff;
    border-right:solid 1px #999;
    border-bottom:solid 1px #999;
    border-left:solid 1px #fff;
}
.PagerStyle span
{
    font-weight:bold;
    color:#333;
    text-decoration:none;
    padding:2px 10px 2px 10px;
}
/*RowStyles*/
.RowStyle td, .AltRowStyle td, .SelectedRowStyle td, .EditRowStyle td 
{
    padding: 5px;
    border-right: solid 1px #999;
}
.RowStyle td
{
    background-color:#E4E4E4;
}
.AltRowStyle td
{
    background-color: #fff;
}
.SelectedRowStyle td
{
    background-color:#FF9;
}

Here's the Gridview Html:

<asp:GridView ID="testers" runat="server" style=" top: 200px; position: absolute;"   CssClass="GridViewStyle"       
            AllowPaging="True" PageSize="20" Width="806px"
     GridLines="None">

            <RowStyle CssClass="RowStyle" />
            <EmptyDataRowStyle CssClass="EmptyRowStyle" />
            <PagerStyle CssClass="PagerStyle" />
            <SelectedRowStyle CssClass="SelectedRowStyle" />
            <HeaderStyle CssClass="HeaderStyle"  />
            <EditRowStyle CssClass="EditRowStyle" />
            <AlternatingRowStyle CssClass="AltRowStyle" />
             <Columns>
        <asp:CommandField ShowSelectButton="True" ButtonType="Image" 
                     SelectImageUrl="~/Images/glass.png" Visible="False" >
                 <ControlStyle Height="30px" Width="50px" />
                 </asp:CommandField>
        <asp:CommandField ShowEditButton= "True"  ButtonType="Image" 
                     EditImageUrl="~/Images/rate.jpg" Visible="False"  >
                 <ControlStyle Height="30px" Width="60px" />
                 </asp:CommandField>
        <asp:CommandField ShowDeleteButton ="True" DeleteText="Contact" >
        
                 <ControlStyle Height="30px" Width="60px" />
                 </asp:CommandField>
        
        </Columns>
        </asp:GridView>

Any help would be greatly appreciated.