Omeka has encountered an error

Zend_Db_Select_Exception

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

#0 /var/www/html/omeka-1.5.3/application/libraries/Zend/Db/Select.php(336): Zend_Db_Select->_join('inner join', Array, 'isp.item_id = i...', Array, NULL)
#1 /var/www/html/omeka-1.5.3/themes/vfhindianarchive/custom.php(263): Zend_Db_Select->joinInner(Array, 'isp.item_id = i...', Array)
#2 [internal function]: filter_items_by_exhibit(Object(Omeka_Db_Select), Array)
#3 /var/www/html/omeka-1.5.3/application/libraries/Omeka/Plugin/Broker.php(156): call_user_func_array('filter_items_by...', Array)
#4 /var/www/html/omeka-1.5.3/application/libraries/Omeka/Plugin/Broker.php(182): Omeka_Plugin_Broker->callHook('item_browse_sql', Array)
#5 [internal function]: Omeka_Plugin_Broker->__call('item_browse_sql', Array)
#6 [internal function]: Omeka_Plugin_Broker->item_browse_sql(Object(Omeka_Db_Select), Array)
#7 /var/www/html/omeka-1.5.3/application/libraries/globals.php(215): call_user_func_array(Array, Array)
#8 /var/www/html/omeka-1.5.3/application/libraries/Omeka/Db/Table.php(557): fire_plugin_hook('item_browse_sql', Object(Omeka_Db_Select), Array)
#9 /var/www/html/omeka-1.5.3/application/libraries/Omeka/Db/Table.php(320): Omeka_Db_Table->_fireBrowseSqlHook(Object(Omeka_Db_Select), Array)
#10 /var/www/html/omeka-1.5.3/application/libraries/Omeka/Db/Table.php(282): Omeka_Db_Table->getSelectForFindBy(Array)
#11 /var/www/html/omeka-1.5.3/application/helpers/ItemFunctions.php(113): Omeka_Db_Table->findBy(Array, 1)
#12 /var/www/html/omeka-1.5.3/themes/vfhindianarchive/custom.php(161): get_items(Array, 1)
#13 /var/www/html/omeka-1.5.3/themes/vfhindianarchive/index.php(16): vfh_exhibit_builder_display_featured_exhibit(2)
#14 /var/www/html/omeka-1.5.3/application/libraries/Omeka/View.php(113): include('/var/www/html/o...')
#15 /var/www/html/omeka-1.5.3/application/libraries/Zend/View/Abstract.php(888): Omeka_View->_run('/var/www/html/o...')
#16 /var/www/html/omeka-1.5.3/application/libraries/Zend/Controller/Action/Helper/ViewRenderer.php(900): Zend_View_Abstract->render('index.php')
#17 /var/www/html/omeka-1.5.3/application/controllers/IndexController.php(24): Zend_Controller_Action_Helper_ViewRenderer->renderScript('index.php')
#18 /var/www/html/omeka-1.5.3/application/libraries/Zend/Controller/Action.php(516): IndexController->indexAction()
#19 /var/www/html/omeka-1.5.3/application/libraries/Zend/Controller/Dispatcher/Standard.php(295): Zend_Controller_Action->dispatch('indexAction')
#20 /var/www/html/omeka-1.5.3/application/libraries/Zend/Controller/Front.php(954): Zend_Controller_Dispatcher_Standard->dispatch(Object(Zend_Controller_Request_Http), Object(Zend_Controller_Response_Http))
#21 /var/www/html/omeka-1.5.3/application/libraries/Zend/Application/Bootstrap/Bootstrap.php(97): Zend_Controller_Front->dispatch()
#22 /var/www/html/omeka-1.5.3/application/libraries/Zend/Application.php(366): Zend_Application_Bootstrap_Bootstrap->run()
#23 /var/www/html/omeka-1.5.3/application/libraries/Omeka/Core.php(165): Zend_Application->run()
#24 /var/www/html/omeka-1.5.3/index.php(28): Omeka_Core->run()
#25 {main}