I am using the WebDialogWindow with Modal=True.  When the Modal pops up, even though it is much smaller than the total screen area, it adds about a full screen's worth of blank space to the bottom of the website and causes the page to be able to scroll down when it shouldn't.  This only happens in Internet Explorer 7.  It seems to work fine in IE9 and Google Chrome.

Here's my sample code:

<%@ Page Title="Home Page" Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true"
CodeFile="Default.aspx.cs" Inherits="_Default" %>

<%@ Register Assembly="Infragistics4.Web.v12.2, Version=12.2.20122.2014, Culture=neutral, PublicKeyToken=7dd5c3163f2cd0cb"
Namespace="Infragistics.Web.UI.LayoutControls" TagPrefix="ig" %>

<%@ Register Assembly="Infragistics4.Web.v12.2, Version=12.2.20122.2014, Culture=neutral, PublicKeyToken=7dd5c3163f2cd0cb"
Namespace="Infragistics.Web.UI" TagPrefix="ig" %>
<%--ScriptManager--%>
<asp:Content ID="HeaderContent" runat="server" ContentPlaceHolderID="HeadContent">
</asp:Content>
<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent">
<ig:WebScriptManager ID="WebScriptManager1" runat="server">
</ig:WebScriptManager>
<ig:WebDialogWindow ID="wdwTest" runat="server" Height="300px" Width="400px" Modal="true" WindowState="Hidden">
<ContentPane>
<Template>
<div>
<asp:Button ID="btnClose" Text="Close" runat="server" OnClick="CloseWDW" />
</div>
</Template>
</ContentPane>
</ig:WebDialogWindow>
<asp:Button ID="btnOpen" Text="Open" runat="server" OnClick="OpenWDW" />
<br />
</asp:Content>

 --------

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

using Infragistics.Documents.Excel;
using System.IO;
using System.Data.OleDb;

public partial class _Default : System.Web.UI.Page
{
System.Data.DataTable tblDates = new System.Data.DataTable();

protected void Page_Load(object sender, EventArgs e)
{

}

protected void OpenWDW(object sender, EventArgs e)
{
wdwTest.WindowState = Infragistics.Web.UI.LayoutControls.DialogWindowState.Normal;
}

protected void CloseWDW(object sender, EventArgs e)
{
wdwTest.WindowState = Infragistics.Web.UI.LayoutControls.DialogWindowState.Hidden;
}
}