Index: admin/system_presets/simple/users_u.php
===================================================================
--- admin/system_presets/simple/users_u.php	(revision 14476)
+++ admin/system_presets/simple/users_u.php	(working copy)
@@ -108,14 +108,14 @@
 	// hide columns in grids
 	$hide_columns = Array (
 //		currently not in user
-//		'Default'	=>	Array ('Login', 'LastName', 'FirstName', 'Email', 'PrimaryGroup', 'CreatedOn'),
+//		'Default'	=>	Array ('Login', 'LastName', 'FirstName', 'Email', 'PrimaryGroup', 'CreatedOn', 'Modified'),
 
 //		user selector
-//		'UserSelector' => Array ('Login', 'LastName', 'FirstName', 'Email', 'PrimaryGroup', 'CreatedOn'),
+//		'UserSelector' => Array ('Login', 'LastName', 'FirstName', 'Email', 'PrimaryGroup', 'CreatedOn', 'Modified'),
 
 //		admins list; section: Users Management -> Administrators
 //		'Admins' => Array ('PortalUserId', 'Login', 'FirstName', 'LastName', 'Email'),
 
 //		users list; section: Users Management -> Users
-		'RegularUsers' => Array (/*'PortalUserId', 'Login', 'FirstName', 'LastName', 'Email',*/ 'PrimaryGroup', 'CreatedOn', /* 'Status'*/),
+		'RegularUsers' => Array (/*'PortalUserId', 'Login', 'FirstName', 'LastName', 'Email',*/ 'PrimaryGroup', 'CreatedOn', 'Modified', /* 'Status'*/),
 	);
Index: core/admin_templates/users/users_edit.tpl
===================================================================
--- core/admin_templates/users/users_edit.tpl	(revision 14476)
+++ core/admin_templates/users/users_edit.tpl	(working copy)
@@ -83,9 +83,10 @@
 			<inp2:m_RenderElement name="inp_edit_options" prefix="u" field="Country" title="la_fld_Country" has_empty="1"/>
 			<inp2:m_RenderElement name="inp_edit_multioptions" prefix="u" field="DisplayToPublic" title="la_fld_DisplayToPublic"/>
 
-		<inp2:m_RenderElement name="subsection" prefix="u" fields="Status,CreatedOn" title="la_section_Properties"/>
+		<inp2:m_RenderElement name="subsection" prefix="u" fields="Status,CreatedOn,Modified" title="la_section_Properties"/>
 			<inp2:m_RenderElement name="inp_edit_radio" prefix="u" field="Status" title="la_fld_Status"/>
 			<inp2:m_RenderElement name="inp_edit_date_time" prefix="u" field="CreatedOn" title="la_fld_CreatedOn"/>
+			<inp2:m_RenderElement name="inp_edit_date_time" prefix="u" field="Modified" title="la_fld_Modified"/>
 
 		<inp2:m_if check="m_ModuleEnabled" module="In-Portal">
 			<!-- custom fields: begin -->
Index: core/install/upgrades.sql
===================================================================
--- core/install/upgrades.sql	(revision 14487)
+++ core/install/upgrades.sql	(working copy)
@@ -2039,4 +2039,8 @@
 
 UPDATE Phrase
 SET l<%PRIMARY_LANGUAGE%>_Translation = 'User name length (min - max)'
-WHERE PhraseKey = 'LA_TEXT_MIN_USERNAME' AND l<%PRIMARY_LANGUAGE%>_Translation = 'Minimum user name length';
\ No newline at end of file
+WHERE PhraseKey = 'LA_TEXT_MIN_USERNAME' AND l<%PRIMARY_LANGUAGE%>_Translation = 'Minimum user name length';
+
+# ===== v 5.1.3 =====
+UPDATE PortalUser
+SET Modified = NULL;
\ No newline at end of file
Index: core/units/users/users_config.php
===================================================================
--- core/units/users/users_config.php	(revision 14489)
+++ core/units/users/users_config.php	(working copy)
@@ -393,7 +393,7 @@
 							        ),
 							        'ResourceId' => Array('type' => 'int','not_null' => 1, 'default' => 0),
 							        'Status' => Array('type' => 'int', 'formatter'=>'kOptionsFormatter', 'options'=>Array(1=>'la_Enabled', 0=>'la_Disabled', 2=>'la_Pending'), 'use_phrases'=>1, 'not_null' => 1, 'default' => 1),
-							        'Modified' => Array('type' => 'int', 'formatter' => 'kDateFormatter', 'default' => '#NOW#'),
+							        'Modified' => Array('type' => 'int', 'formatter' => 'kDateFormatter', 'default' => NULL),
 							        'dob' => Array('type'=>'int', 'formatter' => 'kDateFormatter', 'default' => NULL),
 							        'tz' => Array('type' => 'int', 'default' => NULL),
 							        'ip' => Array('type' => 'string', 'not_null' => 1, 'default' => ''),
@@ -495,6 +495,7 @@
 									'Email'			=> Array( 'title'=>'la_col_Email', 'filter_block' => 'grid_like_filter'),
 									'PrimaryGroup'	=> Array( 'title'=>'la_col_PrimaryGroup', 'filter_block' => 'grid_like_filter'),
 									'CreatedOn'	=>	Array('title' => 'la_col_CreatedOn', 'filter_block' => 'grid_date_range_filter'),
+									'Modified'	=>	Array('title' => 'la_col_Modified', 'filter_block' => 'grid_date_range_filter'),
 									'Status'		=> Array ('title' => 'la_col_Status', 'filter_block' => 'grid_options_filter', 'width' => 100, ),
 								),
 						),
@@ -514,6 +515,7 @@
 								'Email'			=> Array ('title' => 'la_col_Email', 'filter_block' => 'grid_like_filter', 'width' => 200, ),
 								'PrimaryGroup'	=> Array( 'title'=>'la_col_PrimaryGroup', 'filter_block' => 'grid_like_filter', 'width' => 100, ),
 								'CreatedOn'	=>	Array('title' => 'la_col_CreatedOn', 'filter_block' => 'grid_date_range_filter', 'width' => 150, ),
+								'Modified'	=>	Array('title' => 'la_col_Modified', 'filter_block' => 'grid_date_range_filter', 'width' => 150, ),
 								'Status'		=> Array ('title' => 'la_col_Status', 'filter_block' => 'grid_options_filter', 'width' => 100, ),
 							),
 						),
@@ -551,6 +553,7 @@
 								'PrimaryGroup'	=> Array ('title' => 'la_col_PrimaryGroup', 'filter_block' => 'grid_like_filter', 'width' => 140),
 								'Status'		=> Array ('title' => 'la_col_Status', 'filter_block' => 'grid_options_filter', 'width' => 100, ),
 								'CreatedOn'		=> Array ('title' => 'la_col_CreatedOn', 'filter_block' => 'grid_date_range_filter', 'width' => 100),
+								'Modified'		=> Array ('title' => 'la_col_Modified', 'filter_block' => 'grid_date_range_filter', 'width' => 100),
 							),
 						),
 					),
Index: core/units/users/users_event_handler.php
===================================================================
--- core/units/users/users_event_handler.php	(revision 14489)
+++ core/units/users/users_event_handler.php	(working copy)
@@ -930,6 +930,12 @@
 			/* @var $object UsersItem */
 
 			$object->setLogin();
+			$changed_fields = array_keys( $object->GetChangedFields() );
+
+			if ( $changed_fields && !in_array('Modified', $changed_fields) ) {
+				$object->SetDBField('Modified_date', adodb_mktime());
+				$object->SetDBField('Modified_time', adodb_mktime());
+			}
 		}
 
 		/**