Magento/paypal bug fixed - repost

Hi, Need someone to fix this magento error from one day to the next when you go through the checkout process and click order you normally get redirected to PayPal to pay but now get this error: Fatal error: Call to a member function validate() on a non-object in /home/xxxxxxx/public_html/app/code/core/Mage/Paypal/Model/[login to view URL] on line 137 Need someone to fix asap. I am sure a quick project for someone that knows how.