diff -up ./front/fileupload.php.old ./front/fileupload.php
--- ./front/fileupload.php.old	2015-02-27 10:03:26.350805386 +0100
+++ ./front/fileupload.php	2015-02-27 10:04:09.149972196 +0100
@@ -66,7 +66,7 @@ $errors =  array(
         'min_height'          => __('Image requires a minimum height')
     );
 
-$upload_handler = new UploadHandler(array('upload_dir'        => GLPI_ROOT.'/files/_tmp/',
+$upload_handler = new UploadHandler(array('upload_dir'        => GLPI_TMP_DIR.'/',
                                           'param_name'        => $_GET['name'],
                                           'orient_image'      => false,
                                           'image_versions'    => array()),
diff -up ./inc/html.class.php.old ./inc/html.class.php
--- ./inc/html.class.php.old	2015-02-27 10:03:34.849838511 +0100
+++ ./inc/html.class.php	2015-02-27 10:04:27.798044878 +0100
@@ -5118,7 +5118,7 @@ class Html {
          && is_array($p['values']['filename']) && count($p['values']['filename'])) {
          foreach ($p['values']['filename'] as $key => $name) {
             if (isset($p['values']['tag'][$key])) {
-               $file = GLPI_ROOT.'/files/_tmp/'.$p['values']['filename'][$key];
+               $file = GLPI_TMP_DIR.'/'.$p['values']['filename'][$key];
                if (file_exists($file)) {
                   $display = sprintf('%1$s %2$s', $p['values']['filename'][$key],
                                                   Toolbox::getSize(filesize($file)));