[Lynne]

You still don't have your ids correct. This is from the article, look at the stuff in red - they must all be the same:

<td id="custommenu" class="vbmenu_control">
    <a href="#">Custom Menu</a>
    <script type="text/javascript">
        vbmenu_register("custommenu");
    </script>
</td>

<div class="vbmenu_popup" id="custommenu_menu" style="display:none">
<table cellpadding="4" cellspacing="1" border="0">
        <tr>
            <td class="thead">Custom Menu</td>
        </tr>
        <tr>
            <td class="vbmenu_option" title="nohilite">
content row
</td>
</tr>
</table>
</div>

Also, you have two <td> and </td> tags in your code so remove one in that part of your code like this:

<table>
<tr>
<td id="custommenu1" class="vbmenu_control">
    <a href="#">Custom Menu1</a>
    <script type="text/javascript">
        vbmenu_register("custommenu1");
    </script>
</td><td id="custommenu2" class="vbmenu_control">
    <a href="#">Custom Menu2</a>
    <script type="text/javascript">
        vbmenu_register("custommenu2");
    </script>
</td>
</tr>
</table>