Using PEAR::Console_Getopt, 0 is not seen as an argument. For example: "./test.php --opt=0" gives:
error: Console_Getopt: option --opt requires an argument

The expected result would be:

Array
(
    [0] => Array
        (
            [0] => Array
                (
                    [0] => --opt
                    [1] => 0
                )

        )

    [1] => Array
        (
        )

)

Regards
Lars Munch