[jQuery] Jumpy, unpredictable hover() in Firefox

[dazonic]

Hi, I've got some hover effects in my menu that go a bit crazy, only
in Firefox. It works fine in Safari (and IE, I'm fairly sure).

//=======================================================
// I slimmed this code down, but it's the same..

// Hide submenu only if it's not current, or not parent of current

$("#menu .trigger:not(.current_parent, .current) > ul").hide();

// .trigger will slide open submenu only if it's not current, or not
parent of current

submenuTrigger = $("#menu .trigger:not(.current_parent, .current)");

submenu = $("#menu .trigger > ul");

// Open submenu on hover over trigger

submenuTrigger.hover(function() {
  submenu.slideDown(500);
}, function() {
  // do nothing
} );

// Close submenu on hover away from #menu

submenuTrigger.parent().hover(function() {
  // do nothing
}, function() {
  submenu.slideUp(500);
});

//====================================================

<div id="menu">
<ul>
  <li><a href="#">Home</a></li>
  <li><a href="#">Line up</a></li>
  <li class="trigger current_parent"><a href="#">Competitions</a></li>
    <ul>
      <li class="current"><a href="#">Kiteboarding</a></li>
      <li><a href="#">BMX</a></li>
      <li><a href="#">Skate</a></li>
      <li><a href="#">Scooters</a></li>
      <li><a href="#">Bikini and Boardshorts</a></li>
      <li><a href="#">Coconet Cuties</a></li>
    </ul>
  <li><a href="#">Get Involved!</a></li>
  <li><a href="#">Accommodation</a></li>
  <li><a href="#">Contact Us</a></li>
</ul>
</div>

//==========================================================

Link: http://coconetclassic.net.au/

Thanks for your help!

Daz