Index: branches/RC/core/kernel/db/dbitem.php
===================================================================
diff -u -N -r10294 -r10334
--- branches/RC/core/kernel/db/dbitem.php	(.../dbitem.php)	(revision 10294)
+++ branches/RC/core/kernel/db/dbitem.php	(.../dbitem.php)	(revision 10334)
@@ -982,10 +982,16 @@
 		}
 	}
 
+	/**
+	 * Determines, that changes made to this item should be written to change log
+	 *
+	 * @return bool
+	 */
 	function ShouldLogChanges()
 	{
-		/* @todo Replace true with global LogChanges option */
-		return ($this->Application->getUnitOption($this->Prefix, 'LogChanges') || true) && !$this->Application->getUnitOption($this->Prefix, 'ForceDontLogChanges');
+		$log_changes = $this->Application->getUnitOption($this->Prefix, 'LogChanges') || $this->Application->ConfigValue('UseChangeLog');
+
+		return $log_changes && !$this->Application->getUnitOption($this->Prefix, 'ForceDontLogChanges');
 	}
 
 	function LogChanges($main_prefix, $mode)
Index: branches/RC/core/units/admin/admin_events_handler.php
===================================================================
diff -u -N -r10145 -r10334
--- branches/RC/core/units/admin/admin_events_handler.php	(.../admin_events_handler.php)	(revision 10145)
+++ branches/RC/core/units/admin/admin_events_handler.php	(.../admin_events_handler.php)	(revision 10334)
@@ -32,7 +32,7 @@
 			'OnRebuildThemes', 'OnCheckPrefixConfig',
 		);
 
-		if ($this->Application->isDebugMode() && in_array($event->Name, $system_events)) {
+		if ($this->Application->isDebugMode(false) && in_array($event->Name, $system_events)) {
 			return true;
 		}
 
Index: branches/RC/core/kernel/utility/unit_config_reader.php
===================================================================
diff -u -N -r10134 -r10334
--- branches/RC/core/kernel/utility/unit_config_reader.php	(.../unit_config_reader.php)	(revision 10134)
+++ branches/RC/core/kernel/utility/unit_config_reader.php	(.../unit_config_reader.php)	(revision 10334)
@@ -235,8 +235,14 @@
 //		if (!$this->ProcessAllConfigs) return ;
 		$this->FinalStage = true;
 		foreach ($this->configData as $prefix => $config) {
-			if (in_array($prefix, $this->AfterConfigProcessed)) continue;
-			$this->Application->HandleEvent( new kEvent($prefix.':OnAfterConfigRead') );
+			if (in_array($prefix, $this->AfterConfigProcessed)) {
+				continue;
+			}
+
+			$event = new kEvent($prefix.':OnAfterConfigRead');
+			$event->setEventParam('top_prefix', $this->Application->GetTopmostPrefix($event->Prefix, true));
+			$this->Application->HandleEvent($event);
+
 			$this->AfterConfigProcessed[] = $prefix;
 		}
 
@@ -307,8 +313,14 @@
 		// call OnAfterConfigRead for cloned configs
 		$new_clones = array_unique($new_clones);
 		foreach ($new_clones as $prefix) {
-			if (in_array($prefix, $this->AfterConfigProcessed)) continue;
-			$this->Application->HandleEvent( new kEvent($prefix.':OnAfterConfigRead') );
+			if (in_array($prefix, $this->AfterConfigProcessed)) {
+				continue;
+			}
+
+			$event = new kEvent($prefix.':OnAfterConfigRead');
+			$event->setEventParam('top_prefix', $this->Application->GetTopmostPrefix($event->Prefix, true));
+			$this->Application->HandleEvent($event);
+
 			$this->AfterConfigProcessed[] = $prefix;
 		}
 	}
@@ -653,7 +665,9 @@
 			array_unshift($clones, $prefix);
 			$clones = array_unique($clones);
 			foreach ($clones as $a_prefix) {
-				$this->Application->HandleEvent( new kEvent($a_prefix.':OnAfterConfigRead') );
+				$event = new kEvent($a_prefix.':OnAfterConfigRead');
+				$event->setEventParam('top_prefix', $this->Application->GetTopmostPrefix($event->Prefix, true));
+				$this->Application->HandleEvent($event);
 			}
 		}
 	}
Index: branches/RC/core/kernel/application.php
===================================================================
diff -u -N -r10274 -r10334
--- branches/RC/core/kernel/application.php	(.../application.php)	(revision 10274)
+++ branches/RC/core/kernel/application.php	(.../application.php)	(revision 10334)
@@ -2226,16 +2226,23 @@
 	 * @access public
 	 * @author Kostja / Alex
 	 */
-	function GetTopmostPrefix($current_prefix, $real_top=false)
+	function GetTopmostPrefix($current_prefix, $real_top = false)
 	{
 		// 1. get genealogical tree of $current_prefix
 		$prefixes = Array ($current_prefix);
 		while ( $parent_prefix = $this->getUnitOption($current_prefix, 'ParentPrefix') ) {
+			if (!$this->prefixRegistred($parent_prefix)) {
+				// stop searching, when parent prefix is not registered
+				break;
+			}
+
 			$current_prefix = $parent_prefix;
 			array_unshift($prefixes, $current_prefix);
 		}
 
-		if ($real_top) return $current_prefix;
+		if ($real_top) {
+			return $current_prefix;
+		}
 
 		// 2. find what if parent is passed
 		$passed = explode(',', $this->GetVar('all_passed'));