setTimeout () moving div with iframe causing flicker in firefox only

[recoder]

I have a horizontal scroll animation in javascript that works in IE
and Chrome, however I get a flicker in Firefox 2 and 3. The div
that is moving contains an iframe with images and text with absolutely
positioned divs.

The javascript is:

<script type="text/javascript">

/* outtake:
function scrollframeleft() {
var divmenuleft = getLeft("divMenu");
var framewidth = parent.frames["framecontent"].scrollwidth;
var scrollportal = 740;
var scrollCatch = 13;

if (!noScroll && divmenuleft <=scrollCatch) {
divMenuObjStyle.left=(divmenuleft+scrollDistVar)+'px'
t = setTimeout("scrollframeleft();",scrollSpeedVar)
}
}
</script>

The HTML :

<div id="divBg" style="position:absolute; z-index:10; top:415px; left:
13px; width:740px; height:100px; clip:rect(0px 740px 102px 13px);
visibility:visible;">
<div id="divMenu" style="position:absolute; z-index:10; top:0px; left:
13px; color:#FFFFFF; visibility:visible;">
<iframe name="framecontent" id="framecontent" frameborder="0"
height="100" width="5000" scrolling="no" src="/content.php"></
iframe>
</div>
</div>


Thanks for your support!

 

[recoder]

to clarify the problem:

1) The content appearing in either the div to the left or the right of
the animating div appears to flicker. I moved my arrows above the
horizontal where the animation occurs, but I still see a flicker on
the side where the style.left is moving under the adjacent divs.


2) It seems that when using the mouseover handler for approximately 10
seconds (on my computer) in FIREFOX ONLY the animation pauses, and
then starts again. This does not occur in either IE or Chrome. (It
seems to be building up too many calls for the processor (?) but not
sure about this theory as I am running a fast Intel processor with 2
GB of RAM ) Has anyone else seen this issue?


<div id="divArrowLeft" style="position:absolute; z-index:204; left:
136px; top:398px;"><a href="#" onmouseover="noScroll=false;
scrollframeleft()" onmouseout="noMove()" onclick="void blur()" ><img
src="/images/leftarrow_sm.gif" width="14" height="14" alt="more news
scroll left" border="0"> </a></div>


Is this a problem with my code above?

Is there a Firefox specific work around for either of these issues?