diff --git a/core/mutex.class.inc.php b/core/mutex.class.inc.php
index 82e67dd60..ea459d0bf 100644
--- a/core/mutex.class.inc.php
+++ b/core/mutex.class.inc.php
@@ -133,7 +133,9 @@ class iTopMutex
 		}
 		if (($res !== '1') && ($res !== '0'))
 		{
-			IssueLog::Error('GET_LOCK('.$this->sName.', 0) returned: '.var_export($res, true).'. Expected values are: 0, 1 or null !!');
+			$sMsg = 'GET_LOCK('.$this->sName.', 0) returned: '.var_export($res, true).'. Expected values are: 0, 1 or null';
+			IssueLog::Error($sMsg);
+			throw new Exception($sMsg);
 		}
 		return ($res !== '0');
 	}
diff --git a/datamodels/2.x/itop-backup/ajax.backup.php b/datamodels/2.x/itop-backup/ajax.backup.php
index 24020c7b5..6e92249fc 100644
--- a/datamodels/2.x/itop-backup/ajax.backup.php
+++ b/datamodels/2.x/itop-backup/ajax.backup.php
@@ -1,5 +1,5 @@
 <?php
-// Copyright (C) 2014 Combodo SARL
+// Copyright (C) 2013-2015 Combodo SARL
 //
 //   This file is part of iTop.
 //
@@ -19,7 +19,7 @@
 /**
  * Backup from an interactive session
  *
- * @copyright   Copyright (C) 2013 Combodo SARL
+ * @copyright   Copyright (C) 2013-215 Combodo SARL
  * @license     http://opensource.org/licenses/AGPL-3.0
  */
 
@@ -119,7 +119,9 @@ EOF
 		{
 			$sEnvironment = utils::ReadParam('environment', 'production', false, 'raw_data');
 			$oRestoreMutex = new iTopMutex('restore.'.$sEnvironment);
+			IssueLog::Info("Backup Restore - Acquiring the LOCK 'restore.$sEnvironment'");
 			$oRestoreMutex->Lock();
+			IssueLog::Info('Backup Restore - LOCK acquired, executing...');
 			try
 			{
 				set_time_limit(0);
@@ -144,6 +146,7 @@ EOF
 				$sBackupFile = $sBackupDir.$sFile;
 				$sRes = $oDBRS->RestoreFromZip($sBackupFile, $sEnvironment);
 	
+				IssueLog::Info('Backup Restore - Done, releasing the LOCK');
 				$oRestoreMutex->Unlock();
 			}
 			catch (Exception $e)
diff --git a/datamodels/2.x/itop-backup/main.itop-backup.php b/datamodels/2.x/itop-backup/main.itop-backup.php
index 2ea3f914a..d2cc37afa 100644
--- a/datamodels/2.x/itop-backup/main.itop-backup.php
+++ b/datamodels/2.x/itop-backup/main.itop-backup.php
@@ -1,5 +1,5 @@
 <?php
-// Copyright (C) 2014 Combodo SARL
+// Copyright (C) 2014-2015 Combodo SARL
 //
 //   This program is free software; you can redistribute it and/or modify
 //   it under the terms of the GNU General Public License as published by
@@ -26,7 +26,6 @@ class BackupHandler extends ModuleHandlerAPI
 {
 	public static function OnMetaModelStarted()
 	{
-
 		try
 		{
 			$oBackupMutex = new iTopMutex('backup.'.utils::GetCurrentEnvironment());
@@ -48,13 +47,14 @@ class BackupHandler extends ModuleHandlerAPI
 			}
 			else
 			{
+				IssueLog::Info(__class__.'::'.__function__.' A user is trying to use iTop while a restore is running. The requested page is in read-only mode.');
 				MetaModel::GetConfig()->Set('access_mode', ACCESS_READONLY, 'itop-backup');
 				MetaModel::GetConfig()->Set('access_message', ' - '.dict::S('bkp-restore-running'), 'itop-backup');
 			}
 		}
 		catch(Exception $e)
 		{
-			
+			IssueLog::Error(__class__.'::'.__function__.' Failed to check if a backup/restore is running: '.$e->getMessage());
 		}
 	}
 }