Severe lag time while adding to cart...

I've been racking my brain trying to figure out a problem I'm having with Firefox and Chrome and the eCart_PHP.php include...

We are using version 4.5.2 of eCart with a server having php 5 and mysql 5. We are feeding the details from all the products from our database. We do not have a login feature of any type of external session (outside of eCart).

When you navigate to the site with Firefox, (www.changecompanies.net) all DB fed pages work fine, when I add products to the cart(mee.php) they add fine on most browsers. For the most part. Firefox for PC, Mac and Linux along with Chrome for Mac and PC have tendencies to lag upwards of two minutes when either loading a page with the eCart_PHP.php require, coming back to the cart after a few minutes of doing something else OR clicking the "Continue Shopping" button on the cart page. There are only a few things in common with all those pages;

jquery.min.js
addthis.js
visistat.js (3rd party tracking)

I have eliminated all of the above variables and still have the same issues. It's not like it DOESN'T happen, it DOES it just takes a while to complete the page load. The problem is the almost same across the affected browsers below. I've tested the pages in question on the following OS/browser combinations:

PC
- Firefox - errors (not the same frequency as other installs of firefox on different OS's)
- Safari - good!
- Opera - good!
- Chrome - errors
- IE 6, 7 & 8 - good! SURPRISE

Ubuntu
- Firefox - errors

Mac
- Safari - good
- Chrome - errors
- Firefox - errors

I've even loaded the backup of our old site that has the "add to cart" buttons hard coded on each page with none of the javascript files and still get the same errors...

Question to the WebAssist Team...

Is there some sort of connection with the database left open? Are there too many connections open? A loop not working right? Anything else I can't think of...

Any help would rock!

Ted