[jQuery] UL Hover menu

[jQuery] UL Hover menu


Hi there,
I'm trying to create a hover dropdown many with jQuery and all seems
to work fine in safari but not in ie7?
The idea is that when I hover over the main li the sub ul appears and
slides down. When I hover over the main li is works as planned but
then on ie7 when I move the mouse down to the sub ul is slide back
up???
jQuery:
<script type="text/javascript">
    $(document).ready(function() {
        // hide sub menus
        $('ul.col_one_subnav').hide();
        // toggle sub menus on hover
        $('.col_one_navigation li').toggle(function() {
            $(this).children('ul:hidden').slideDown();
            }, function() {
            $(this).children('ul:visible').slideUp();
        });
    });
</script>
HTML:
<ul class="col_one_navigation">
    <li><a href="" title="">Blackboard</a>
    <ul class="col_one_subnav">
    <li><a href="" title="">Blackboard</a></
li>
<li><a href="" title="">Blackboard</
a></li>
<li><a href="" title="">Blackboard</
a></li>
</ul>
</li>
<li><a href="" title="">Placements</a></li>
<li><a href="" title="">Student Union</a></li>
</ul>
Can anyone help.
Thanks.
TJ