[jQuery] MSIE 7.0 and slide() function...

[jQuery] MSIE 7.0 and slide() function...


Hi :)
I'm working on my website, just to practice a bit with jquery.
I have a problem here:
http://www.andreavarnier.com/temp
menu code is like this
    <ul id="menu">
        <li id="here"><a href="index.html">Home</a></li>
        <li class="open_sub"><a href="#">Musica</a>
            <ul class="sub">
                <li><a href="audio.html">audio</a></li>
                <li><a href="spartiti.html">spartiti</a></li>
                <li><a href="lezioni.html">lezioni</a></li>
            </ul>
        </li>
        <li class="open_sub"><a href="#">Andrea</a>
            <ul class="sub">
                <li><a href="curriculum.html">curriculum</a></li>
                <li><a href="foto.html">foto</a></li>
                <li><a href="video.html">video</a></li>
            </ul>
        </li>
        <li><a href="guestbook/">Guestbook</a></li>
        <li><a href="links.html">Links</a></li>
        <li><a href="contatti.html">Contatti</a></li>
    </ul>
and the js I'm using is fairly simple:
$(document).ready(function(){
    $(".sub").css("display", "none");
    $(".open_sub").click(function(){
        var f = $(".open_sub").not(this);
        f.children("ul.sub:visible").slideUp();
        f.removeClass("active");
        var t = $(this);
        t.children("ul.sub").slideToggle();
        t.toggleClass("active");
    });
});
with Internet Explorer 7 the submenus do not disappear until the
slide() effect is over.
this means the <li>'s are overlapping each other.
is there a known workaround? I searched this mailing list but I didn't
find anything...
thank you in advance :)
andrea