jQuery Bugs... Help Fix

I have two problems, both of them are minor but really important to me.

The first one is with the quotes. When you change tabs or dont have focus on the site, then when u come back it just loads everything that u missed at once really fast.

The code is:

<script type="text/javascript">
$(document).ready(function() {
$("#random").load("http://spatialvoid.net/includes/slogan.php");
var refreshId = setInterval(function() {
$("#random").fadeOut('slow', function() {
$(this).load("http://spatialvoid.net/includes/slogan.php?switch", function() {
$(this).fadeIn('slow');
});
});
}, 5000);
$.ajaxSetup({ cache: false });
});
</script>

The other problem is with using nixbox’s lavalamp. Sometimes, the lava background is located slightly offsetted, why is this? How to fix that, thanks.

This is the site: SpatialVoid :: Premium Custom Designing