Scriptaculous onmouseover event fire delay

I am using scriptaculous to cause images in a menu to grow then shrink again.  There are several images arranged in a vertical column.  I use the following functions, which are called for the events onmouseover and onmouseout:

function popIn(item) {
      new Effect.Scale(item, 64, {scaleFromCenter:true, duration: .1, queue:'end'});
}
           
function popOut(item) {
      new Effect.Scale(item, 150, {scaleFromCenter:true, duration: .1, queue:'end'});
}

When a user starts at the top and moves towards the bottom every image pops out and then in before the image we are looking for...  I want to make it so that prior to actually popping out that the user is required to keep their mouse hovering over the image for a specified amount of time.

The image's code looks like this:

<img src=th_img_74.jpg'  onmouseover = "popOut(this);" onmouseout="popIn(this);" />

The actual url is http://www.sscautos.com/dev/photos.php.  Any ideas?  Does this make sense?