You cannot define a correlation name 'category_idx' more than once

#0 /data/htdocs2/lib/Varien/Db/Select.php(281): Zend_Db_Select->_join('inner join', Array, 'category_idx.ca...', Array, NULL)
#1 /data/htdocs2/app/code/core/Zend/Db/Select.php(352): Varien_Db_Select->_join('inner join', Array, 'category_idx.ca...', Array, NULL)
#2 /data/htdocs2/app/code/core/Zend/Db/Select.php(331): Zend_Db_Select->joinInner(Array, 'category_idx.ca...', Array, NULL)
#3 /data/htdocs2/app/code/local/GoMage/Navigation/Model/Resource/Eav/Mysql4/Layer/Filter/Category.php(42): Zend_Db_Select->join(Array, 'category_idx.ca...', Array)
#4 /data/htdocs2/app/code/local/GoMage/Navigation/Model/Resource/Eav/Mysql4/Layer/Filter/Category.php(59): GoMage_Navigation_Model_Resource_Eav_Mysql4_Layer_Filter_Category->prepareSelect(Object(GoMage_Navigation_Model_Catalog_Layer_Filter_Category), Array, Object(Varien_Db_Select))
#5 /data/htdocs2/app/code/local/GoMage/Navigation/Model/Catalog/Layer/Filter/Category.php(136): GoMage_Navigation_Model_Resource_Eav_Mysql4_Layer_Filter_Category->applyFilterToCollection(Object(GoMage_Navigation_Model_Catalog_Layer_Filter_Category), Array)
#6 /data/htdocs2/app/code/core/Mage/Catalog/Block/Layer/Filter/Abstract.php(91): GoMage_Navigation_Model_Catalog_Layer_Filter_Category->apply(Object(Mage_Core_Controller_Request_Http), Object(GoMage_Navigation_Block_Catalog_Layer_Filter_Category))
#7 /data/htdocs2/app/code/core/Mage/Catalog/Block/Layer/Filter/Abstract.php(73): Mage_Catalog_Block_Layer_Filter_Abstract->_initFilter()
#8 /data/htdocs2/app/code/core/Mage/Catalog/Block/Layer/View.php(117): Mage_Catalog_Block_Layer_Filter_Abstract->init()
#9 /data/htdocs2/app/code/local/GoMage/Navigation/Block/Catalog/Layer/View.php(81): Mage_Catalog_Block_Layer_View->_prepareLayout()
#10 /data/htdocs2/app/code/core/Mage/Core/Block/Abstract.php(297): GoMage_Navigation_Block_Catalog_Layer_View->_prepareLayout()
#11 /data/htdocs2/app/code/core/Mage/Core/Model/Layout.php(456): Mage_Core_Block_Abstract->setLayout(Object(Mage_Core_Model_Layout))
#12 /data/htdocs2/app/code/core/Mage/Core/Model/Layout.php(472): Mage_Core_Model_Layout->createBlock('gomage_navigati...', 'gomage.catalog....')
#13 /data/htdocs2/app/code/core/Mage/Core/Model/Layout.php(239): Mage_Core_Model_Layout->addBlock('gomage_navigati...', 'gomage.catalog....')
#14 /data/htdocs2/app/code/core/Mage/Core/Model/Layout.php(205): Mage_Core_Model_Layout->_generateBlock(Object(Mage_Core_Model_Layout_Element), Object(Mage_Core_Model_Layout_Element))
#15 /data/htdocs2/app/code/core/Mage/Core/Model/Layout.php(210): Mage_Core_Model_Layout->generateBlocks(Object(Mage_Core_Model_Layout_Element))
#16 /data/htdocs2/app/code/core/Mage/Core/Controller/Varien/Action.php(344): Mage_Core_Model_Layout->generateBlocks()
#17 /data/htdocs2/app/code/core/Mage/Catalog/controllers/CategoryController.php(148): Mage_Core_Controller_Varien_Action->generateLayoutBlocks()
#18 /data/htdocs2/app/code/core/Mage/Core/Controller/Varien/Action.php(418): Mage_Catalog_CategoryController->viewAction()
#19 /data/htdocs2/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(254): Mage_Core_Controller_Varien_Action->dispatch('view')
#20 /data/htdocs2/app/code/core/Mage/Core/Controller/Varien/Front.php(172): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#21 /data/htdocs2/app/code/core/Mage/Core/Model/App.php(381): Mage_Core_Controller_Varien_Front->dispatch()
#22 /data/htdocs2/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#23 /data/htdocs2/index.php(97): Mage::run('', 'store')
#24 {main}