mouse wheel scrolling work with f5 in app but don't work on web

Good day! I have a web application on Silverlight 3. on ManePage I have a

<ScrollViewer  x:Name="sV" MouseWheel="sV_MouseWheel" VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Auto">

with such code:

private void sV_MouseWheel(object sender, 开发者_开发问答MouseWheelEventArgs e)
        {
            var offset = sV.VerticalOffset;
            sV.ScrollToVerticalOffset(offset + (e.Delta * -0.5));
        }

When I press F5 button to debug my application, mouse wheel scrolling works well, but when I press F6 and then choose Web.Project prperty Debug->Start New Instance or publish my project on site, mouse wheel scrolling doesn't work :(

what can I do?

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oh, it works in IE, but doesn't work in other browsers