Item (Mage_Catalog_Model_Product) with the same id "31" already exist

#0 /home/multismart/domains/multismart.nl/public_html/app/code/core/Mage/Eav/Model/Entity/Collection/Abstract.php(265): Varien_Data_Collection->addItem(Object(Mage_Catalog_Model_Product))
#1 /home/multismart/domains/multismart.nl/public_html/app/code/core/Mage/Eav/Model/Entity/Collection/Abstract.php(1056): Mage_Eav_Model_Entity_Collection_Abstract->addItem(Object(Mage_Catalog_Model_Product))
#2 /home/multismart/domains/multismart.nl/public_html/app/code/core/Mage/Eav/Model/Entity/Collection/Abstract.php(871): Mage_Eav_Model_Entity_Collection_Abstract->_loadEntities(false, false)
#3 /home/multismart/domains/multismart.nl/public_html/lib/Varien/Data/Collection.php(741): Mage_Eav_Model_Entity_Collection_Abstract->load()
#4 /home/multismart/domains/multismart.nl/public_html/app/design/frontend/gadgetsgift/default/template/page/homepage.phtml(176): Varien_Data_Collection->getIterator()
#5 /home/multismart/domains/multismart.nl/public_html/app/code/core/Mage/Core/Block/Template.php(241): include('/home/multismar...')
#6 /home/multismart/domains/multismart.nl/public_html/app/code/core/Mage/Core/Block/Template.php(272): Mage_Core_Block_Template->fetchView('frontend/gadget...')
#7 /home/multismart/domains/multismart.nl/public_html/app/code/core/Mage/Core/Block/Template.php(286): Mage_Core_Block_Template->renderView()
#8 /home/multismart/domains/multismart.nl/public_html/app/code/core/Mage/Core/Block/Abstract.php(923): Mage_Core_Block_Template->_toHtml()
#9 /home/multismart/domains/multismart.nl/public_html/app/code/core/Mage/Core/Model/Layout.php(555): Mage_Core_Block_Abstract->toHtml()
#10 /home/multismart/domains/multismart.nl/public_html/app/code/core/Mage/Core/Controller/Varien/Action.php(390): Mage_Core_Model_Layout->getOutput()
#11 /home/multismart/domains/multismart.nl/public_html/app/code/core/Mage/Cms/Helper/Page.php(137): Mage_Core_Controller_Varien_Action->renderLayout()
#12 /home/multismart/domains/multismart.nl/public_html/app/code/core/Mage/Cms/Helper/Page.php(52): Mage_Cms_Helper_Page->_renderPage(Object(Mage_Cms_IndexController), 'home')
#13 /home/multismart/domains/multismart.nl/public_html/app/code/core/Mage/Cms/controllers/IndexController.php(45): Mage_Cms_Helper_Page->renderPage(Object(Mage_Cms_IndexController), 'home')
#14 /home/multismart/domains/multismart.nl/public_html/app/code/core/Mage/Core/Controller/Varien/Action.php(418): Mage_Cms_IndexController->indexAction()
#15 /home/multismart/domains/multismart.nl/public_html/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(254): Mage_Core_Controller_Varien_Action->dispatch('index')
#16 /home/multismart/domains/multismart.nl/public_html/app/code/core/Mage/Core/Controller/Varien/Front.php(172): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#17 /home/multismart/domains/multismart.nl/public_html/app/code/core/Mage/Core/Model/App.php(365): Mage_Core_Controller_Varien_Front->dispatch()
#18 /home/multismart/domains/multismart.nl/public_html/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#19 /home/multismart/domains/multismart.nl/public_html/index.php(105): Mage::run('', 'store')
#20 {main}