Just want to let you know all how I fixed multisite for easingslider. Not the best solution probably but it works. Just make sure each site has a slider with the same name, in my case that’s “Homepage”:
<?php if ( function_exists( "easingslider" ) ) {
$posttitle = 'homepage';
$postid = $wpdb->get_var( "SELECT ID FROM $wpdb->posts WHERE post_type = 'easingslider' AND LOWER(post_title) = '" . $posttitle . "'" );
easingslider( intval($postid) );
} ?>
Good luck! 😉