Widget instance options not showing correctly

i finally found the answer, its actually not a problem with the code i posted. its in the update() function. i have some validation code

function update($new_instance, $old_instance) {
    $instance['title'] = esc_attr(strip_tags($new_instance['title']));
    if (is_int($new_instance['number_products'])) {
        if ($new_instance['number_products'] > 0)
            $instance['number_products'] = $new_instance['number_products'];
        else
            $instance['number_products'] = 1;
    } else {
        $instance['number_products'] = $old_instance['number_product'];
    }

    return $instance;
}

the problem is at 2 places. i should be using is_numeric over is_int, the reason is

To test if a variable is a number or a
numeric string (such as form input,
which is always a string), you must
use is_numeric().

then, in the else, $old_instance['number_product'] should have be plural $old_instance['number_products']

error code: 523