Well, the problem turned out to be operator precedence in my return statement, as indicated by japhy and bart. Basically, using:

    return  $va->[0] <=> $vb->[0]
    ||      $va->[1] cmp $vb->[1];
[download]

or:

    return ($va->[0] <=> $vb->[0]
            or $va->[1] cmp $vb->[1]);
[download]

does the trick.

japhy also pointed out an improved version of the Orcish Maneuver, while bart suggests that the improved version needs a new name, and that I should link to the subtopic so helpful PerlMonks don't have to chase wild geese in order to help me. And another thank you to planetscape for showing me how to properly link to a subtopic here.

Thanks all!

--roboticus