Switch Menu slow refresh (persistent)

[spider3]

Script Title: Switch Menu

Script URL (on DD):
http://www.dynamicdrive.com/dynamici...switchmenu.htm

Example of the problem on my page:
http://www.scs-software.ch/new/
(try clicking on Finanzbuchhaltung or wertschriften)

Hi everyone,
I need help to resolve a problem about the Switch menu being slow when configured persistent on more page.
I need to open a new page when I click on a main menu, and at the same time, I want to expand the menu.
I've used the following code to perform this action:

<a href="../financial_d.html" class="menulink">
<div class="menutitle2" onclick="SwitchMenu('sub2')"><img src="../images/arrow.gif" border="0" />&nbsp;&nbsp;Finanzbuchhaltung</div></a>

The scripts is working but it's performing very slow. If there is no cookies registered for the script, and the browser cache it's empy, the users can see a very slow loading of the menu (like the page is refreshing 2 times, one for the new page, and one to expand the menu).

I've also noted that on certain computers are a bit slower/faster than the other, but the lag is anyway too much.

There is a way I can adapt/modify the script to avoid this?

Thank you a lot,

Spider

[spider3]

Noone? *sigh*
I hope to find a fix to avoid this problem, this menu is very practical.
Thank you for your help.