PHP Drop Down hierarchy issues

Questions
1

My site http://www.forschungsallianz-system-mensch.de/ has an issue with its drop-down menus. Excuse this being a noob issue, but I am completely foxed by it.

The menu bar on my site will only display sub pages from within their parent page. I have formatted some of the Menu headings to link to sub-pages, but I want all of the available sub pages to appear whenever a menu heading is hover selected.

Thanks,

Michael

<ul class="menu">	

    <% loop $Menu(1) %>
        <li>
            <a href="$Link" title="Go to the $Title page" class="<% if $isCurrent %>current<% else_if $isSection %>section<% end_if %>">
                $MenuTitle
            </a>

            <% if $isSection %>
                <% if $Children %>
                    <ul class="secondary">
                        <% loop $Children %>
                            <li class="<% if $isCurrent %>current<% else_if $isSection %>section<% end_if %>"><a href="$Link">$MenuTitle</a></li>
                        <% end_loop %>
                    </ul>
                <% end_if %>
            <% end_if %>
        </li>
    <% end_loop %>
</ul>
</div>