We're using Joomla! 1.5.20 on our site and the the JA_Edenite template. We have some JavaScript errors on the site that I hope you may help me solve. It seems to be related to the template. When opening the site in IE8, I get this error:

Stop running this script?

A script on this page is causing Internet Explorer to run slowly. If it continues to run, your computer might become unresponsive.
It started yesterday. I've not changed the template, but we have done other things lately, like switching server in order to make nBill work.

If I change the template, the error goes away, I think. Maybe I've done some terrible alterations to the template without knowing?

I got a tip to use Firebug to figure out whats wrong. As far as I can see it detects two errors:

$("ja-botsl") is null
makeEqualHeight ($('ja-botsl').getChildren());

this.elements is undefined
for (var i=0;i<this.elements.length;i++) {

I'm not familiar with JavaScript and have no idea how to fix this! Can you give me some directions?

Another problem that I discovered today: It's a delay from when I edit items like articles until the changes are displayed at the site. If I log into frontend, I see the changes right away. This might be related?

Could anybody help me figuring out what's wrong and how to fix this?
Thank you!