diff --git a/install/INSTALL.txt b/install/INSTALL.txt
index 64d4d71..477f2ab 100644
--- a/install/INSTALL.txt
+++ b/install/INSTALL.txt
@@ -234,5 +234,7 @@ cat  calcmsOld.sql | mysql -u root calcmsOld
 cat  calcmsNew.sql | mysql -u root calcmsNew
 
 mysqldiff --force --changes-for=server2 --difftype=sql calcmsOld:calcmsNew > migrate.sql
+# make sure lines with "modified_at" contain "ON UPDATE CURRENT_TIMESTAMP"
+# for example: `modified_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
 cat migrate | mysql -u root calcms
 
diff --git a/install/create.sql b/install/create.sql
index dc1cdd5..66d39ef 100644
--- a/install/create.sql
+++ b/install/create.sql
@@ -37,7 +37,7 @@ CREATE TABLE `calcms_audio_recordings` (
   `rmsRight` float DEFAULT NULL,
   `mastered` tinyint(1) DEFAULT '0',
   `processed` tinyint(1) DEFAULT '0',
-  `modified_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  `modified_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
   PRIMARY KEY (`id`),
   KEY `project_index` (`project_id`),
   KEY `studio_index` (`studio_id`),
@@ -142,7 +142,7 @@ CREATE TABLE `calcms_event_history` (
   `excerpt` longtext,
   `content` longtext,
   `modified_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
-  `created_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
+  `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
   `rating` int(11) DEFAULT NULL,
   `status` varchar(40) DEFAULT NULL,
   `visibility` varchar(40) DEFAULT NULL,
@@ -227,7 +227,7 @@ CREATE TABLE `calcms_events` (
   `excerpt` longtext,
   `content` longtext,
   `modified_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
-  `created_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
+  `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
   `rating` int(11) DEFAULT NULL,
   `status` varchar(40) DEFAULT NULL,
   `visibility` varchar(40) DEFAULT NULL,
@@ -303,14 +303,14 @@ DROP TABLE IF EXISTS `calcms_images`;
 /*!40101 SET character_set_client = utf8 */;
 CREATE TABLE `calcms_images` (
   `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
-  `created_at` datetime DEFAULT NULL,
+  `created_at` datetime DEFAULT CURRENT_TIMESTAMP,
   `description` text,
   `name` varchar(300) DEFAULT NULL,
   `filename` varchar(64) NOT NULL,
   `created_by` varchar(64) DEFAULT NULL,
   `studio_id` int(10) unsigned DEFAULT NULL,
   `modified_by` varchar(64) DEFAULT NULL,
-  `modified_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  `modified_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
   `project_id` int(10) unsigned NOT NULL,
   PRIMARY KEY (`id`),
   KEY `created_at` (`created_at`),
@@ -525,8 +525,8 @@ CREATE TABLE `calcms_roles` (
   `read_role` tinyint(1) unsigned DEFAULT NULL,
   `update_role` tinyint(1) unsigned DEFAULT NULL,
   `delete_user` tinyint(1) unsigned DEFAULT NULL,
-  `created_at` timestamp NULL DEFAULT NULL,
-  `modified_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  `created_at` timestamp NULL DEFAULT CURRENT_TIMESTAMP,
+  `modified_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
   `update_event_of_series` tinyint(1) unsigned DEFAULT NULL,
   `update_event_of_others` tinyint(1) unsigned DEFAULT NULL,
   `studio_id` int(10) unsigned NOT NULL,
@@ -622,10 +622,10 @@ CREATE TABLE `calcms_series` (
   `image` varchar(200) DEFAULT NULL,
   `project` varchar(64) DEFAULT NULL,
   `location` varchar(100) DEFAULT NULL,
-  `modified_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  `modified_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
   `modified_by` varchar(100) NOT NULL,
   `category` varchar(60) DEFAULT NULL,
-  `created_at` timestamp NULL DEFAULT NULL,
+  `created_at` timestamp NULL DEFAULT CURRENT_TIMESTAMP,
   `assign_event_series_name` varchar(100) DEFAULT NULL,
   `assign_event_title` varchar(100) DEFAULT NULL,
   `default_duration` int(10) unsigned DEFAULT NULL,
@@ -843,8 +843,8 @@ CREATE TABLE `calcms_studios` (
   `location` varchar(100) NOT NULL,
   `stream` varchar(100) NOT NULL,
   `google_calendar` varchar(100) NOT NULL,
-  `created_at` timestamp NULL DEFAULT NULL,
-  `modified_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  `created_at` timestamp NULL DEFAULT CURRENT_TIMESTAMP,
+  `modified_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
   `image` varchar(200) NOT NULL,
   PRIMARY KEY (`id`) USING BTREE,
   UNIQUE KEY `name_2` (`name`),
@@ -902,7 +902,7 @@ CREATE TABLE `calcms_user_events` (
   `title` varchar(200) DEFAULT NULL,
   `excerpt` longtext,
   `content` longtext,
-  `modified_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  `modified_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
   `modified_by` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
   `status` varchar(40) DEFAULT NULL,
   `program` varchar(40) DEFAULT NULL,
@@ -938,8 +938,8 @@ CREATE TABLE `calcms_user_roles` (
   `user_id` int(10) unsigned NOT NULL,
   `role_id` int(10) unsigned NOT NULL,
   `studio_id` int(10) unsigned NOT NULL DEFAULT '0',
-  `created_at` timestamp NULL DEFAULT NULL,
-  `modified_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  `created_at` timestamp NULL DEFAULT CURRENT_TIMESTAMP,
+  `modified_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
   `project_id` int(10) unsigned NOT NULL,
   PRIMARY KEY (`id`) USING BTREE,
   KEY `user_id` (`user_id`),
@@ -972,7 +972,7 @@ CREATE TABLE `calcms_user_series` (
   `series_id` int(10) unsigned NOT NULL,
   `active` char(1) NOT NULL,
   `modified_by` varchar(100) DEFAULT NULL,
-  `modified_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  `modified_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
   `studio_id` int(10) unsigned NOT NULL,
   `project_id` int(10) unsigned NOT NULL,
   PRIMARY KEY (`id`),
@@ -1069,8 +1069,8 @@ CREATE TABLE `calcms_users` (
   `salt` varchar(32) NOT NULL,
   `pass` varchar(100) NOT NULL,
   `email` varchar(300) DEFAULT NULL,
-  `modified_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
-  `created_at` timestamp NULL DEFAULT NULL,
+  `modified_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+  `created_at` timestamp NULL DEFAULT CURRENT_TIMESTAMP,
   `disabled` int(10) unsigned DEFAULT '0',
   `session_timeout` int(10) unsigned NOT NULL DEFAULT '120',
   `created_by` varchar(30) DEFAULT NULL,
diff --git a/install/migrate.sql b/install/migrate.sql
index 6c27fbe..3d6565e 100644
--- a/install/migrate.sql
+++ b/install/migrate.sql
@@ -31,3 +31,53 @@ ALTER TABLE `calcms_series_schedule`
   CHANGE COLUMN start_offset start_offset int(11) NULL DEFAULT '0', 
   CHANGE COLUMN nextDay nextDay int(11) NULL DEFAULT '0';
 
+ALTER TABLE `calcms_audio_recordings` 
+  CHANGE COLUMN modified_at modified_at timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP;
+
+
+ALTER TABLE `calcms_event_history` 
+  CHANGE COLUMN created_at created_at timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP;
+
+
+ALTER TABLE `calcms_events` 
+  CHANGE COLUMN created_at created_at timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP;
+
+
+ALTER TABLE `calcms_images` 
+  CHANGE COLUMN created_at created_at datetime NULL DEFAULT CURRENT_TIMESTAMP, 
+  CHANGE COLUMN modified_at modified_at timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP;
+
+
+ALTER TABLE `calcms_roles` 
+  CHANGE COLUMN modified_at modified_at timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP, 
+  CHANGE COLUMN created_at created_at timestamp NULL DEFAULT CURRENT_TIMESTAMP;
+
+
+ALTER TABLE `calcms_series` 
+  CHANGE COLUMN created_at created_at timestamp NULL DEFAULT CURRENT_TIMESTAMP, 
+  CHANGE COLUMN modified_at modified_at timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP;
+
+
+ALTER TABLE `calcms_studios` 
+  CHANGE COLUMN created_at created_at timestamp NULL DEFAULT CURRENT_TIMESTAMP, 
+  CHANGE COLUMN modified_at modified_at timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP;
+
+
+ALTER TABLE `calcms_user_events` 
+  CHANGE COLUMN modified_at modified_at timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP;
+
+
+ALTER TABLE `calcms_user_roles` 
+  CHANGE COLUMN created_at created_at timestamp NULL DEFAULT CURRENT_TIMESTAMP, 
+  CHANGE COLUMN modified_at modified_at timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP;
+
+
+ALTER TABLE `calcms_user_series` 
+  CHANGE COLUMN modified_at modified_at timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP;
+
+
+ALTER TABLE `calcms_users` 
+  CHANGE COLUMN created_at created_at timestamp NULL DEFAULT CURRENT_TIMESTAMP, 
+  CHANGE COLUMN modified_at modified_at timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP;
+
+
diff --git a/lib/calcms/audio_recordings.pm b/lib/calcms/audio_recordings.pm
index 5af1045..802251a 100644
--- a/lib/calcms/audio_recordings.pm
+++ b/lib/calcms/audio_recordings.pm
@@ -140,6 +140,10 @@ sub update{
                rmsLeft=?, rmsRight=?
         where  project_id=? and studio_id=? and event_id=?
     };
+    if (defined $entry->{id}){
+        $query.=' and id=?';
+        push @$bind_values, $entry->{id};
+    }
     #print STDERR Dumper($query).Dumper($bind_values);
     return db::put($dbh, $query, $bind_values);
 }