Ciao a tutti ho questo script per far scorrere il testo in verticale

<style type="text/css">
#marqueecontainer{
position: relative;
width: 200px; /*marquee width */
height: 180px; /*marquee height */
background-color: white;
overflow: hidden;
border: 3px solid #E2E1E1;
}
</style>
<script type="text/javascript">
var delayb4scroll=2000
var marqueespeed=1
var pauseit=1
var copyspeed=marqueespeed
var pausespeed=(pauseit==0)? copyspeed: 0
var actualheight=''
function scrollmarquee(){
if (parseInt(cross_marquee.style.top)>(actualheight*(-1)+8))
cross_marquee.style.top=parseInt(cross_marquee.sty le.top)-copyspeed+"px"
else
cross_marquee.style.top=parseInt(marqueeheight)+8+ "px"
}
function initializemarquee(){
cross_marquee=document.getElementById("vmarquee")
cross_marquee.style.top=0
marqueeheight=document.getElementById("marqueecont ainer").offsetHeight
actualheight=cross_marquee.offsetHeight
if (window.opera || navigator.userAgent.indexOf("Netscape/7")!=-1){
cross_marquee.style.height=marqueeheight+"px"
cross_marquee.style.overflow="scroll"
return
}
setTimeout('lefttime=setInterval("scrollmarquee()" ,30)', delayb4scroll)
}
if (window.addEventListener)
window.addEventListener("load", initializemarquee, false)
else if (window.attachEvent)
window.attachEvent("onload", initializemarquee)
else if (document.getElementById)
window.onload=initializemarquee
</script>

nel body

<div id="marqueecontainer" onMouseover="copyspeed=pausespeed" onMouseout="copyspeed=marqueespeed">
<div id="vmarquee" style="width: 98%;height:180px;position:relative;padding-left: 2px;padding-right: 2px; text-align: justify; font-size: 7pt;">
testo
</div></div>

in IE va ma in Firefox dopo un po che scorre salta anche se non è arrivato in fondo e riparte dall'inizio...

vedete dov'è l'errore?

grazie