Index: shipping_event_handler.php
===================================================================
--- shipping_event_handler.php	(revision 13919)
+++ shipping_event_handler.php	(working copy)
@@ -36,6 +36,12 @@
 	 */
 	function OnAfterItemLoad(&$event)
 	{
+		parent::OnAfterItemLoad($event);
+
+		if (!$this->Application->isAdminUser) {
+			return ;
+		}
+
 		$object =& $event->getObject();
 
 		$format = '%01.'.$object->GetDBField('PrecisionAfterSep').'f'; // %01.2f
@@ -44,6 +50,7 @@
 		$sc_object =& $this->Application->recallObject('sc', null, Array ('raise_warnings' => 0));
 		/* @var $sc_object kDBItem */
 
+		// change default shipping cost values ("Costs" tab on shipping editing) based on field from "Shipping Type"
 		$flat_options = $sc_object->GetFieldOptions('Flat');
 		$flat_options['format'] = $format;
 		$flat_options['default'] = $zero_if_empty ? 0 : null;