Index: branches/version-2_4-dev/data/class/db/dbfactory/SC_DB_DBFactory_MYSQL.php
===================================================================
--- branches/version-2_4-dev/data/class/db/dbfactory/SC_DB_DBFactory_MYSQL.php	(revision 18388)
+++ branches/version-2_4-dev/data/class/db/dbfactory/SC_DB_DBFactory_MYSQL.php	(revision 18679)
@@ -243,6 +243,8 @@
      */
     function sfChangeTrunc($sql){
-        $changesql = eregi_replace("( TRUNC)", " TRUNCATE", $sql);
-        return $changesql;
+        if (preg_match('/TRUNCATE/i', $sql)) {
+            return $sql;
+        }
+        return eregi_replace("( TRUNC)", " TRUNCATE", $sql);
     }