Hello, the icon of desktop shortcut doesnt appear on IE.

heres the code

CSS file
.shortcut-icon
{
    width: 48px;
    height: 48px;
}
.icon-teste
{    
    background-image: url( ../img/icones/48_iphone_icons.png ) !important;    
    filter: progid:DXImageTransform.Microsoft.AlphaImageLoader(src="../img/icones/48_iphone_icons.png", sizingMethod="scale");
}
ASP
<ext:Desktop ID="MyDesktop" runat="server" BackgroundColor="Black" ShortcutTextColor="White">
        <Shortcuts>
            <ext:DesktopShortcut ShortcutID="customF" Text="Call server" IconCls="shortcut-icon icon-teste" />
        </Shortcuts>
    </ext:Desktop>
The shortcut icon appears on ly in FF, in IE only appears the label.

Does someone knows Why?