Index: trunk/core/kernel/utility/unit_config_reader.php
===================================================================
diff -u -r4380 -r4418
--- trunk/core/kernel/utility/unit_config_reader.php	(.../unit_config_reader.php)	(revision 4380)
+++ trunk/core/kernel/utility/unit_config_reader.php	(.../unit_config_reader.php)	(revision 4418)
@@ -123,7 +123,7 @@
 				// when merging empty array to non-empty results non-empty array, but empty is required
 				foreach ($sub_config as $sub_key => $sub_value) {
 					if (!$sub_value) {
-						unset($this->configData[$sub_config][$sub_key]);
+						unset($this->configData[$sub_prefix][$sub_key]);
 					}
 				}