A guess
 
    From the code you show I am guessing you are using the form_alter hook to modify an existing form
    and add an addition submit button and well as a custom submit handler.
 
    Since only one of the submit handlers can actually return a path (a least only one is used), if
    my guess is correct try replacing your return at the end of the submit function with
 
    $_REQUEST['destination'] = "AllDotDev/alldotdev_groups_display/" . $query_string . "/" . $pagerrows;
 
Steve Ringwood
Nevets Software