diff --git a/dblayer.php b/dblayer.php
index 0b50512..6a33624 100644
--- a/dblayer.php
+++ b/dblayer.php
@@ -274,8 +274,14 @@ class dblayer extends PDO
         //." ". dgettext("domframework","in")." ".$key);
         continue;
       }
+   
       // Check for type inconsistencies if the value is provided
-      if (! is_string ($datas[$key]))
+      if (is_null ($datas[$key]))
+      {
+        // Skipped the removed autoincrement keys
+        continue;
+      }
+      elseif (! is_string ($datas[$key]))
       {
         $errors[$key] = array ("error", sprintf (
                             dgettext("domframework",
@@ -449,7 +455,6 @@ class dblayer extends PDO
       }
     }
 
-$this->debug = 1;
     // Check if the foreign keys constrains are valid before doing the insertion
     foreach ($this->foreign as $foreign=>$data)
     {