Index: branches/RC/core/units/general/cat_dbitem_export.php
===================================================================
diff -u -N -r11693 -r11711
--- branches/RC/core/units/general/cat_dbitem_export.php	(.../cat_dbitem_export.php)	(revision 11693)
+++ branches/RC/core/units/general/cat_dbitem_export.php	(.../cat_dbitem_export.php)	(revision 11711)
@@ -1139,6 +1139,11 @@
 		{
 			$object =& $event->getObject( Array('skip_autoload' => true) );
 
+			if (!array_key_exists('ExportColumns', $object->Fields)) {
+				// import/export prefix was used (see kDBEventHandler::prepareObject) but object don't plan to be imported/exported
+				return ;
+			}
+
 			$available_columns = Array();
 
 			if ($this->Application->getUnitOption($event->Prefix, 'CatalogItem')) {