diff --git a/lib/classes/task/Scheduler.class.php b/lib/classes/task/Scheduler.class.php
index 03d85ca820..49b58fda29 100755
--- a/lib/classes/task/Scheduler.class.php
+++ b/lib/classes/task/Scheduler.class.php
@@ -33,6 +33,7 @@ class task_Scheduler
 
     public function __construct(Logger $logger)
     {
+        declare(ticks = 1);
         $this->logger = $logger;
     }
 
@@ -52,6 +53,14 @@ class task_Scheduler
      * @throws Exception if scheduler is already running
      * @todo doc all possible exception
      */
+    public function sigHandler($signal)
+    {
+        $status = null;
+        $pid = pcntl_wait($status);
+        $exitstatus = pcntl_wexitstatus ( $status );
+        $this->log(sprintf("sigchild %s received from pid=%s, status=%s, exitstatus=%s\n", $signal, $pid, var_export($status, true), $exitstatus));
+    }
+
     public function run()
     {
 
@@ -73,7 +82,10 @@ class task_Scheduler
 
         if (\task_manager::isPosixPcntlSupported()) {
             // avoid <defunct> php when a task ends
-            pcntl_signal(SIGCHLD, SIG_IGN);
+            //  pcntl_signal(SIGCHLD, SIG_IGN);     // no zombies but no returnValue
+            //  pcntl_signal(SIGCHLD, SIG_DFL);     // with "declare(ticks=1)" returnValue ok but zombies
+            pcntl_signal(SIGCHLD, array($this, 'sigHandler'));    // ok
+
             $this->method = self::METHOD_FORK;
         }
 
diff --git a/lib/classes/task/period/archive.class.php b/lib/classes/task/period/archive.class.php
index 398a209903..b41914a6e0 100755
--- a/lib/classes/task/period/archive.class.php
+++ b/lib/classes/task/period/archive.class.php
@@ -145,7 +145,7 @@ class task_period_archive extends task_abstract
     public function xml2graphic($xml, $form)
     {
         // XML should always be valid here...
-        if (($sxml = simplexml_load_string($xml)) != false) {
+        if ( ($sxml = simplexml_load_string($xml)) ) {
             // sanitize values
             if ((int) ($sxml->period) < 10) {
                 $sxml->period = 10;
@@ -298,7 +298,7 @@ class task_period_archive extends task_abstract
         $this->period = 60;
         $this->cold = 30;
 
-        if (($this->sxBasePrefs = simplexml_load_string($collection->get_prefs())) != false) {
+        if ( ($this->sxBasePrefs = simplexml_load_string($collection->get_prefs())) ) {
             $this->sxBasePrefs["id"] = $base_id;
 
             $this->period = (int) ($this->sxTaskSettings->period);
@@ -397,7 +397,7 @@ class task_period_archive extends task_abstract
 
                 $this->setLastExecTime();
                 try {
-                    if ( ! ($this->sxTaskSettings = @simplexml_load_string($this->getSettings()))) {
+                    if ( !($this->sxTaskSettings = @simplexml_load_string($this->getSettings())) ) {
                         throw new Exception(sprintf('Error fetching or reading settings of the task \'%d\'', $this->getID()));
                     } else {
                         // copy settings to task, so it's easier to get later
@@ -609,10 +609,10 @@ class task_period_archive extends task_abstract
         if ($this->movedFiles) {
 
             // something happened : a least one file has moved
-            return self::STATE_MAXRECSDONE;
+            return 'MAXRECSDONE';
         } elseif (memory_get_usage() >> 20 > 25) {
 
-            return self::STATE_MAXMEGSREACHED;
+            return 'MAXMEGSREACHED';
         } else {
 
             return 'NORECSTODO';
@@ -693,7 +693,7 @@ class task_period_archive extends task_abstract
         try {
             $listFolder = new CListFolder($path);
 
-            if (($sxDotPhrasea = @simplexml_load_file($path . '/.phrasea.xml')) != false) {
+            if ( ($sxDotPhrasea = @simplexml_load_file($path . '/.phrasea.xml')) ) {
 
                 // test for magic file
                 if (($magicfile = trim((string) ($sxDotPhrasea->magicfile))) != '') {
@@ -800,7 +800,7 @@ class task_period_archive extends task_abstract
 
             $xp = new DOMXPath($dom);
 
-            if (($sxDotPhrasea = @simplexml_load_file($path . '/.phrasea.xml')) != false) {
+            if ( ($sxDotPhrasea = @simplexml_load_file($path . '/.phrasea.xml')) ) {
 
                 // test magicfile
                 if (($magicfile = trim((string) ($sxDotPhrasea->magicfile))) != '') {