truncated display in IE6

[Timo]

I am wondering if anyone has seen behavior like the following in IE: when a
DIV is made visible, now and then not all of its elements are displayed; the
display is truncated. It happens rarely. And the truncation occurs at
different places, sometimes after only two or three elements have been
displayed, sometimes after a dozen.

The DIV contains many elements.

<DIV id='SUBMENU3'>

<div id='anid' class='aclass'>
<div id='someid' class='someclass'>
<img id='animgid' src='blahblah'
onClick='myFunc(this.id);'
onmouseover='someFunc(this.id);'
>
<a href='dfjskfjdfsdfsddsfsdfs'
id='xx' class='aclass'>
As much as 100 characters of text...
</a>
</div>
</div>

{dozens more like this
with the same structure}

</DIV>

Here's how the DIV is made visible:

function showSubMenu(id, previd) {
mydiv=getElementById('SUBMENU' + id);
mydiv.style.display='block';
prevdiv=getElementById('DIV' + previd);
prevdiv.style.display='none';
}

Is the number of elements in the DIV possibly related to the truncation of
the display? Is this a browser memory issue? IE6.

Thanks!