As an alternative you could use the same CssStyle as the row style you wish to preserve. Try using a DOM inspector to check which style is applied to the unselected row, such as Firebug in Firefox or Developer Tools in IE8.

I have discuss the issue with my colleague Yudi, who handle the thread listed. He mention that the above issue has not been solved and Alex H has not replied to us since his last post in the thread or through email.

Perhaps we could try to replicate the issue in our environment to investigate the issue further. Do you mind sharing the enviroment detail you are using to install the product? You already mention that you are using Windows Server 2008 SP2 with .NET Framework 3.5 SP1, is it the 64 bit version or the 32 bit one? 

Using css class as you proposed is the correct way to remove the selected row style. In my test, the different between the selected and unselected row style is the style attribute appended in the cell element. In order to remove the selected style you will need to define an empty css class so the style attribute will be an empty string. The DummyCSS snippet:

<style type="text/css">
    .DummyCSS{ }
</style>

A workaround if you would like to use classic paging would be to retrieve the filtered row count during InitializePostBack server side event handler and invoke javascript function to render the information. Here is the snippet, the client side snippet will try to render a new TD element in the WebGrid status bar:

//Server code
protected void wgTest_InitializePostBack(object sender, PostbackEventArgs e)
{
    switch (e.Action)
    {
        case "ColumnFilter":
            int filterCount = ((System.Data.DataTable)(wgTest.DataSource)).DefaultView.Count;
            wgTest.ClientAction.InvokeScript("RenderFilterCount", new FunctionParameter[] { new FunctionParameter(filterCount.ToString(), "string")}); 
            break;
    }
}

//Client side code
function RenderFilterCount(count)
{
    var grid = ISGetObject("wgTest");
    var customStat = document.getElementById("tdCustomStat_" + grid.Id);

    if (customStat)
    {
        customStat.getElementsByTagName("div")[0].innerHTML = "Filtered row: " + count;
    }
    else
    {
        var statBar = grid.GetElement(WG40.STATUSBAR, WG40.HTMLCELL);

        var filterCountDiv = document.createElement("div");
        filterCountDiv.innerHTML = "Filtered row: " + count;

        var filterCountDivCont = document.createElement("td");
        filterCountDivCont.setAttribute("id", "tdCustomStat_" + grid.Id);
        filterCountDivCont.setAttribute("noWrap", "nowrap");
        filterCountDivCont.appendChild(filterCountDiv);

        var sepElem = statBar.nextSibling;

        sepElem.parentNode.insertBefore(filterCountDivCont, sepElem);
        sepElem.parentNode.insertBefore(sepElem.cloneNode(true), filterCountDivCont);
    }  
}

The ChartImageProcessing event handler could not be used if you wish to add the data or category in the drop zone. You will need to use the Page_Load event handler.

If the ActionName conditional does not work you could try checking if the data or category is already available in the collection and if not add it to the collection. Here is the snippet:

    Sub page_load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
        If wgTest.ChartCategoryCollection.Exists("Interest") = False Then
            wgTest.ChartCategoryCollection.Add(New ChartPivotFilterConfig() With {.DataMember = "Interest"})
            wgTest.ChartDataCollection.Add(New ChartPivotDataConfig() With {.DataMember = "ID"})
        End If
    End Sub