my plugin: http://wordpress.org/extend/plugins/mediapicker-more-rows/
I found a way to fix the pagination
There is a way you can ‘hook’ into paginate_links. There is no official hook for it, but you can change the $wp_query->found_posts variable.
What I did here is ‘hooking’ into the paginate_links by abusing the media_upload_mime_type_links filter and setting a new value for $wp_query->found_posts.
This filter is triggered just before paginate_links is called.
function set_paginate_limit_mediapicker( $type_links )
{
global $wp_query;
$new_limit = 30; // set your limit
$wp_query->found_posts = $wp_query->found_posts / ( $new_limit / 10 );
return $type_links; // not used
}
add_filter( 'media_upload_mime_type_links', 'set_paginate_limit_mediapicker', 1 );
I have made a WordPress plugin for the complete solution, which you will find in the repository.