diff --git a/main/gradebook/index.php b/main/gradebook/index.php
index 58a8b91914..07e5a01fda 100755
--- a/main/gradebook/index.php
+++ b/main/gradebook/index.php
@@ -998,7 +998,7 @@ if (isset($first_time) && $first_time == 1 && api_is_allowed_to_edit(null, true)
                         $table.
                         $graph.
                         '<br />'.get_lang('Feedback').'<br />
-                        <textarea rows="5" cols="100" ></textarea>'
+                        <textarea rows="5" cols="100" >&nbsp;</textarea>'
                     );
                 } else {
                     echo $table;
diff --git a/main/gradebook/lib/be/evaluation.class.php b/main/gradebook/lib/be/evaluation.class.php
index 02f2916897..e380be7f03 100755
--- a/main/gradebook/lib/be/evaluation.class.php
+++ b/main/gradebook/lib/be/evaluation.class.php
@@ -113,7 +113,7 @@ class Evaluation implements GradebookItem
      */
     public function setSessionId($sessionId)
     {
-        $this->sessionId = intval($sessionId);
+        $this->sessionId = (int) $sessionId;
     }
 
     public function get_date()
@@ -153,7 +153,7 @@ class Evaluation implements GradebookItem
 
     public function set_id($id)
     {
-        $this->id = $id;
+        $this->id = (int) $id;
     }
 
     public function set_name($name)
diff --git a/main/gradebook/lib/fe/gradebooktable.class.php b/main/gradebook/lib/fe/gradebooktable.class.php
index bf78f4c769..79a69b2600 100755
--- a/main/gradebook/lib/fe/gradebooktable.class.php
+++ b/main/gradebook/lib/fe/gradebooktable.class.php
@@ -983,7 +983,7 @@ class GradebookTable extends SortableTable
             $imgWebPath = api_get_path(WEB_ARCHIVE_PATH).$chartHash;
 
             if (file_exists($imgSysPath)) {
-                $result = '<div id="contentArea" style="text-align: center;" >';
+                $result = '<br /><div id="contentArea" style="text-align: center;" >';
                 $result .= '<img src="'.$imgWebPath.'" >';
                 $result .= '</div>';
 
diff --git a/main/gradebook/lib/gradebook_data_generator.class.php b/main/gradebook/lib/gradebook_data_generator.class.php
index f1960687f6..431192d33f 100755
--- a/main/gradebook/lib/gradebook_data_generator.class.php
+++ b/main/gradebook/lib/gradebook_data_generator.class.php
@@ -142,6 +142,7 @@ class GradebookDataGenerator
 
                 // Best
                 $best = $this->buildBestResultColumn($item);
+
                 $row['best'] = $best['display'];
                 $row['best_score'] = $best['score'];