Executing prepared PDO statement gives "General error: 10 disk I/O error" (PHP)

            $sql = "REPLACE INTO `myTable` VALUES (:symbol1, :symbol1), (:symbol1, :symbol2)";
            $statement = $this->pdoObject->prepare($sql);
            $statement->execute(array(':symbol1' => $symbol1, ':symbol2' => $symbol2));

The above throws a PDOException:

SQLSTATE[HY000]: General error: 10 disk I/O error