Hvorfor får jeg den fejl

Jeg får følgende fejl: "The DataSourceID of 'faktaboks_table' must be the ID of a control of type IDataSource.  A control with ID 'Faktaboks' could not be found."

Min kode:
Kodebehind:
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public partial class Controls_Faktaboks : System.Web.UI.UserControl {
    private Element _product;
    protected  DataSet _dataSet;
    protected DataTable _dataTable;

    public Element Product {
        get { return _product; }
        set { _product = value; }
    }

    protected void Page_Load(object sender, EventArgs e) {
        _dataSet = new DataSet();
        _dataTable = _dataSet.Tables.Add("Faktaboks");
        _dataTable.Columns.Add("Key", Type.GetType("System.String"));
        _dataTable.Columns.Add("Value", Type.GetType("System.String"));

        DataRow dr = _dataTable.NewRow();
        dr["Key"] = "Key1";
        dr["Value"] = "Value1";
        _dataTable.Rows.Add(dr);

        dr = _dataTable.NewRow();
        dr["Key"] = "Key2";
        dr["Value"] = "Value2";
        _dataTable.Rows.Add(dr);

        dr = _dataTable.NewRow();
        dr["Key"] = "Key3";
        dr["Value"] = "Value3";
        _dataTable.Rows.Add(dr);

        dr = _dataTable.NewRow();
        dr["Key"] = "Key4";
        dr["Value"] = "Value4";
        _dataTable.Rows.Add(dr);
    }
}

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Html-fil:
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<asp:Repeater ID="faktaboks_table"  DataSourceID="Faktaboks" DataSource="<%# _dataSet %>" runat="server">
    <HeaderTemplate>
        <table class="info">
    </HeaderTemplate>
    <ItemTemplate>
        <tr>
            <td class="k">
                <%# Eval("Key") %>
            </td>
            <td class="v">
                <%# Eval("Value")%>
            </td>
        </tr>
    </ItemTemplate>
    <FooterTemplate>
        </table></FooterTemplate>
</asp:Repeater>
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