Using Infragistics35.WebUI.UltraWebNavigator.v8.1.dll

First level menus appear in proper position on the page, even as the source element that triggers their display moves within the browser window's viewport.

But child submenus (2nd level and below) seem to appear in a fixed position based on absolute page coordinates, so that when you scroll the page, the submenus display out of alignment/position with respect to their parent menu.

Is this a bug or is there some property I should be setting on Items to change this behavior?

Here are the declarative tags for the menu:

<ignav:UltraWebMenu ID="uwNavMenu" Cursor="Hand"
ImageDirectory="images/menuImages/" runat="server"
EnhancedRendering="True"
DefaultItemClass="ItemClass"
TopSelectedClass="TopSelected"
DisabledClass="DisabledClass"
DefaultIslandClass="IslandClass"
HoverClass="HoverClass"
TopAligment="Center"
SeparatorClass="SeparatorClass"
BorderStyle="None" BackColor="White"
Height="32px" XPSpacerWidth="0px"
ItemPaddingTop="0" ItemSpacingTop="0"
JavaScriptFileNameCommon=""
LeafItemImageUrl=""
JavaScriptFilename=""
ParentItemImageUrl="" StyleSetName="">
<ItemStyle Width="132px" Height="20px" CssClass="ItemClass" Cursor="Hand"></ItemStyle>
<DisabledStyle ForeColor="white" CssClass="DisabledClass" />
<HoverItemStyle Cursor="Hand" Height="20px" BorderWidth="1px" BorderStyle="Solid" BorderColor="#006600" ForeColor="Black" BackColor="#D8F3DB" CssClass="HoverClass" />
<ExpandEffects ShadowColor="0, 102, 0" Type="Slide" Delay="0" RemovalDelay="20" ShadowWidth="5" />
<IslandStyle Cursor="Default" BorderWidth="1px" Font-Names="Verdana" BorderColor="DimGray"
BorderStyle="Solid" BackColor="#DDDDDD">
<Padding Bottom="0px" Top="0px"></Padding>
</IslandStyle>
<TopSelectedStyle BorderWidth="1px" BorderColor="#006600" BorderStyle="Solid" ForeColor="Black"
BackColor="#D8F3DB" CssClass="TopSelected" />
<SeparatorStyle Height="1px" BackgroundImage="ig_menuSep.gif" BackColor="#006600"
CssClass="SeparatorClass" CustomRules="background-repeat:repeat-x; " />
<Levels>
<ignav:Level Index="0" LevelHoverClass="TopHover" />
<ignav:Level Index="1" />
<ignav:Level Index="2" />
<ignav:Level Index="3" />
</Levels>
<Items>
<ignav:Item Text="" Hidden="true" Styles-Height="33px"></ignav:Item>
<ignav:Item Text="" Hidden="true" Styles-Height="33px"></ignav:Item>
<ignav:Item Text="" Hidden="true" Styles-Height="33px"></ignav:Item>
<ignav:Item Text="" Hidden="true" Styles-Height="33px"></ignav:Item>
<ignav:Item Text="" Hidden="true" Styles-Height="33px"></ignav:Item>
<ignav:Item Text="" Hidden="true" Styles-Height="33px"></ignav:Item>
<ignav:Item Text="" Hidden="true" Styles-Height="33px"></ignav:Item>
<ignav:Item Text="" Hidden="true" Styles-Height="33px"></ignav:Item>
<ignav:Item Text="" Hidden="true" Styles-Height="33px"></ignav:Item>
<ignav:Item Text="" Hidden="true" Styles-Height="33px"></ignav:Item>
</Items>
<Images>
<XPSpacerImage Url="ig_menuXPspacer4.gif" />
<SubMenuImage Url="arrow_right.gif" />
</Images>
<MenuClientSideEvents ItemHover="ItemHover" />
</ignav:UltraWebMenu>