Misaligned menu drop-downs

[Antediluvia]

I'm using VB.NET express 2005 to write a web site. On a master page I have two menus at the top, one below the other, both populated by code. The one on top has several drop-downs, and due to formatting the drop-downs rendered behind the menu below, rather impractical. I fixed this problem by encapsulating each menu in its own Panel and setting the proper z-orders. This worked until recently, and I can't figure out how to get it to work now. Instead the drop-downs render roughly 400 pixels to the right of where they are supposed to. Any help would be appreciated.

If you need any more code (sample rendered page, css, themes) just ask. Give me up to a couple days to respond. TIA.

Edited snippet from master page:

<form id="Form1" runat="server">
        <div class="header" style="z-index: 100;">
            <asp:Panel runat="server" Style="position: relative; left: 156px; top: 0px; z-index: 104;" ID="Panel1">
                <asp:Menu ID="MainMenu" SkinID="MainMenu" runat="server" Height="26px" Orientation="Horizontal"
                    Style="position: static" Width="592px">
                </asp:Menu>
            </asp:Panel>
                
            <asp:Panel runat="server" CssClass="nav" Style="right: 36px; top: 48px; width: 556px;
                text-align: left; z-index: 101; position: absolute;" ID="DIV1">
                <asp:Menu ID="MainMenu2" runat="Server" SkinID="MainMenu2" />
            </asp:Panel>
        </div>
        <table width="904" border="0" cellpadding="4" align="center">
            <tr>
                <td width="904" colspan="2" style="text-align: left">
                    <asp:ContentPlaceHolder ID="ContentPlaceHolder1" runat="server">
                    </asp:ContentPlaceHolder>
                </td>
            </tr>
        </table>
    </form>