diff --git a/main/inc/lib/events.lib.inc.php b/main/inc/lib/events.lib.inc.php
index c75ce8e9a2..9ebebd381c 100644
--- a/main/inc/lib/events.lib.inc.php
+++ b/main/inc/lib/events.lib.inc.php
@@ -47,8 +47,9 @@ function event_open() {
 	//if(!eregi($_configuration['root_web'],$referer))
 	$pos = strpos($referer, $_configuration['root_web']);
 	if ($pos === false && $referer != '') {
-		$remhost = @ getHostByAddr($_SERVER['REMOTE_ADDR']);
-		if ($remhost == $_SERVER['REMOTE_ADDR'])
+		$ip = api_get_real_ip();
+		$remhost = @ getHostByAddr($ip);
+		if ($remhost == $ip)
 			$remhost = "Unknown"; // don't change this
 		$reallyNow = api_get_utc_datetime();
 		$sql = "INSERT INTO ".$TABLETRACK_OPEN."
@@ -77,7 +78,7 @@ function event_login() {
 	$reallyNow = api_get_utc_datetime();
 	$sql = "INSERT INTO ".$TABLETRACK_LOGIN." (login_user_id, login_ip, login_date, logout_date) VALUES	
                 ('".$_user['user_id']."',
-				'".Database::escape_string($_SERVER['REMOTE_ADDR'])."',
+				'".Database::escape_string(api_get_real_ip())."',
 				'".$reallyNow."',
 				'".$reallyNow."'
 				)";
@@ -1445,4 +1446,5 @@ function check_if_mail_already_sent($event_name, $user_from, $user_to = null) {
 }
 
 
-/*  End of filters   */
\ No newline at end of file
+/*  End of filters   */
+
diff --git a/main/inc/lib/main_api.lib.php b/main/inc/lib/main_api.lib.php
index 807d802ba0..cbf27c4132 100644
--- a/main/inc/lib/main_api.lib.php
+++ b/main/inc/lib/main_api.lib.php
@@ -5882,7 +5882,11 @@ function api_block_course_item_locked_by_gradebook($item_id, $link_type, $course
         api_not_allowed(true, $message);
     }
 }
-
+/**
+ * Checks the PHP version installed is enough to run Chamilo
+ * @param string Include path (used to load the error page)
+ * @return void
+ */
 function api_check_php_version($my_inc_path = null) {
     if (!function_exists('version_compare') || version_compare( phpversion(), REQUIRED_PHP_VERSION, '<')) {
         $global_error_code = 1;
@@ -5894,14 +5898,21 @@ function api_check_php_version($my_inc_path = null) {
         exit;
     }
 }
-
+/**
+ * Checks whether the Archive directory is present and writeable. If not,
+ * prints a warning message.
+ */
 function api_check_archive_dir() {
     if (is_dir(api_get_path(SYS_ARCHIVE_PATH)) && !is_writable(api_get_path(SYS_ARCHIVE_PATH))) {
         $message = Display::return_message(get_lang('ArchivesDirectoryNotWriteableContactAdmin'),'warning');
         api_not_allowed(true, $message);
     }
 }
-
+/**
+ * Returns an array of global configuration settings which should be ignored
+ * when printing the configuration settings screens
+ * @return array Array of strings, each identifying one of the excluded settings
+ */
 function api_get_locked_settings() {
     return array(
         'server_type',
@@ -5938,7 +5949,33 @@ function api_get_locked_settings() {
     );
 }
 
+/**
+ * Checks if the user is corrently logged in. Returns the user ID if he is, or
+ * false if he isn't. If the user ID is given and is an integer, then the same
+ * ID is simply returned
+ * @param  integer User ID
+ * @return mixed Integer User ID is logged in, or false otherwise
+ */
 function api_user_is_login($user_id = null) {
     $user_id = empty($user_id) ? api_get_user_id() : intval($user_id);
     return $user_id && !api_is_anonymous();
-}
\ No newline at end of file
+}
+/**
+ * Guess the real ip for register in the database, even in reverse proxy cases.
+ * To be recognized, the IP has to be found in either $_SERVER['REMOTE_ADDR'] or
+ * in $_SERVER['HTTP_X_FORWARDED_FOR'], which is in common use with rproxies.
+ * @return string the real ip of teh user.
+ * @author Jorge Frisancho Jibaja <jrfdeft@gmail.com>, USIL - Some changes to allow the use of real IP using reverse proxy
+ * @version CEV CHANGE 24APR2012
+ */
+function api_get_real_ip(){
+    // Guess the IP if behind a reverse proxy
+    $ip = trim($_SERVER['REMOTE_ADDR']);
+    if (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
+        list($ip1,$ip2) = split(',',$_SERVER['HTTP_X_FORWARDED_FOR']);
+        $ip = trim($ip1);
+    }
+    if ($debug) error_log('Real IP: '.$ip);
+    return $ip;
+}
+