diff --git a/plugins/calendar/calendar.php b/plugins/calendar/calendar.php
index 335c6721..23784170 100644
--- a/plugins/calendar/calendar.php
+++ b/plugins/calendar/calendar.php
@@ -1747,7 +1747,7 @@ class calendar extends rcube_plugin
     $eventid = 'cal:'.$event['id'];
     if (!empty($_SESSION['event_session']) && ($eventid = $_SESSION['event_session']['id'])) {
       $this->rc->plugins->exec_hook('attachments_cleanup', array('group' => $eventid));
-      unset($_SESSION['event_session']);
+      $this->rc->session->remove('event_session');
     }
   }
 
diff --git a/plugins/tasklist/tasklist.php b/plugins/tasklist/tasklist.php
index 6dec0d40..ff99f2e8 100644
--- a/plugins/tasklist/tasklist.php
+++ b/plugins/tasklist/tasklist.php
@@ -162,13 +162,16 @@ class tasklist extends rcube_plugin
             if ($success = $this->driver->create_task($rec)) {
                 $refresh = $this->driver->get_task($rec);
                 if ($temp_id) $refresh['tempid'] = $temp_id;
+                $this->cleanup_task($rec);
             }
             break;
 
         case 'edit':
             $rec = $this->prepare_task($rec);
-            if ($success = $this->driver->edit_task($rec))
+            if ($success = $this->driver->edit_task($rec)) {
                 $refresh = $this->driver->get_task($rec);
+                $this->cleanup_task($rec);
+            }
             break;
 
         case 'delete':
@@ -319,6 +322,21 @@ class tasklist extends rcube_plugin
         return $rec;
     }
 
+
+    /**
+     * Releases some resources after successful save
+     */
+    private function cleanup_task(&$rec)
+    {
+        // remove temp. attachment files
+        $taskid = $rec['id'];
+        if (!empty($_SESSION['tasklist_session']) && ($taskid = $_SESSION['tasklist_session']['id'])) {
+            $this->rc->plugins->exec_hook('attachments_cleanup', array('group' => $taskid));
+            $this->rc->session->remove('tasklist_session');
+        }
+    }
+
+
     /**
      *
      */