Workaround for Jquery Base by Mxperts

Edit 

/app/code/local/Mxperts/Jquery/Block/Page/Html/Head.php

Change 

class Mxperts_Jquery_Block_Page_Html_Head extends Mage_Page_Block_Html_Head

to 

class Mxperts_Jquery_Block_Page_Html_Head extends Fooman_Speedster_Block_Page_Html_Head

Further advice on Jquery: 

Jquery duplicates Magento's inbuilt Javascript library prototype which can add to page load times. If you are concerned about site speed, we recommend replacing extensions that use Jquery as a first step in optimising your site speed. Try finding a replacement solution which is based on the prototype library that comes with default Magento.