Method "frontInitBefore" is not defined in "Ebizmarts_MailChimp_Model_Observer"

#0 /domains/s5.cordings.co.uk/http/app/code/core/Mage/Core/Model/App.php(1360): Mage::throwException('Method "frontIn...')
#1 /domains/s5.cordings.co.uk/http/app/code/core/Mage/Core/Model/App.php(1337): Mage_Core_Model_App->_callObserverMethod(Object(Ebizmarts_MailChimp_Model_Observer), 'frontInitBefore', Object(Varien_Event_Observer))
#2 /domains/s5.cordings.co.uk/http/app/Mage.php(448): Mage_Core_Model_App->dispatchEvent('controller_fron...', Array)
#3 /domains/s5.cordings.co.uk/http/app/code/core/Mage/Core/Controller/Varien/Front.php(128): Mage::dispatchEvent('controller_fron...', Array)
#4 /domains/s5.cordings.co.uk/http/app/code/core/Mage/Core/Model/App.php(764): Mage_Core_Controller_Varien_Front->init()
#5 /domains/s5.cordings.co.uk/http/app/code/core/Mage/Core/Model/App.php(1113): Mage_Core_Model_App->_initFrontController()
#6 /domains/s5.cordings.co.uk/http/app/code/core/Mage/Core/Model/App.php(365): Mage_Core_Model_App->getFrontController()
#7 /domains/s5.cordings.co.uk/http/app/Mage.php(683): Mage_Core_Model_App->run(Array)
#8 /domains/s5.cordings.co.uk/http/index.php(110): Mage::run('', '')
#9 {main}