get_posts() method and paging is not working

Question

Trying to use paging in one of my Wordpress site but seems it is not working.for paging i am using SEO Pager Plugin. here is my code

$params = get_query_var('args'); 
    $ppp = get_option('posts_per_page');
    if (!is_paged()) {
                    $custom_offset = 0;
            } else {
                $custom_offset = $ppp*($paged-1);   
            }
$args = array( 'meta_key' => 'post_author', 'meta_value' => $params ,'numberposts' => $ppp,'offset' => $custom_offset);
        $authorposts=get_posts($args); echo count($authorposts);?>

now i am displaying post results inside the loop and i have placed

<?php SEO_pager(); ?>

outside the loop as per the instructions.I have total 239 posts with a given author but its showing only 5 post and no paging is being shown when i set number numberposts to -1 its showing all the posts but when using the default settings (5) it is showing only 5 posts with no paging options

can any one point where i am doing wrong

Update

I used the following code and paging options came but when i am clicking on any page it showing no result, no sure how can i fix that

$params = get_query_var('args'); 
            $ppp = get_option('posts_per_page');
            $args = array(
                            'meta_key' => 'post_author',
               'meta_value' => $params ,
               'numberposts' => $ppp,
                          'post_type' => 'post',
                         'paged' => ( get_query_var('paged') ? get_query_var('paged') : 1),
                   );

              $authorposts=query_posts($args);

any suggestion what i am doing wrong?

Answer 1

@user702325

Here's how i got it working fine on localhost:

I installed the plugin and set the option Place Pager Automatically in Template on "on". Then in author.php i modified the original query to add some custom parameters. I added this:

global $query_string; // required
$posts = query_posts('posts_per_page=2');

right between rewind_posts(); and get_template_part( 'loop', 'author' );.

That way i could customize the query (in this case i'm showing 2 posts per page) and get the plugin working perfectly.

This test is based on TwentyTen.