WP_Query orderby meta key/value suddely stopped working

Question

I have code that has been working for a long time which when a user clicks a button to order database results by name/value, it gets the results via AJAX from a page that does all the querying.

I have recently moved the entire site to a new dedicated server and changed some javascript files around, but for some reason the ordering has now stopped working. Here is my code:

    if($pageType == 'prize-home'){

    if($orderby == 'pointsvalue'){ //Must have these if statements because if its ordered by pointsvalue, its orderby meta_value_num, but if its a srting (smalltitle) its orderby meta_value
        $my_query = new WP_Query('post_type=prizes&showposts='.$per_page.'&meta_key='.$orderby.'&orderby=meta_value_num&order=asc&paged='.$page);
    }elseif($orderby == 'smalltitle'){
        $my_query = new WP_Query('post_type=prizes&showposts='.$per_page.'&meta_key='.$orderby.'&orderby=meta_value&order=asc&paged='.$page);
    }else{
        $my_query = new WP_Query('post_type=prizes&showposts='.$per_page.'&meta_key=smalltitle&orderby=meta_value&order=asc&paged='.$page);
    }

        while ($my_query->have_posts()) : $my_query->the_post(); $do_not_duplicate = $post->ID; $my_meta = get_post_meta($post->ID,'_my_meta',TRUE); 

        $pointsvalue = get_post_meta($post->ID,'pointsvalue',TRUE);
        $bigtitle = get_post_meta($post->ID,'bigititle',TRUE);
        $smalltitle = get_post_meta($post->ID,'smalltitle',TRUE);
        $productUrl = get_post_meta($post->ID,'producturl',TRUE);
        $imageUrl = get_post_meta($post->ID,'imageurl',TRUE);
        include('profile/prize-style.php'); 

        endwhile;  
        $no_of_paginations = $my_query->max_num_pages;
        wp_reset_query();

It now loads different pages (paginated results) fine, but when the order button is clicked it doesnt really do anything. Some things move about occasionally but it doesnt sort the results alphabetically.

I really dont think I have changed anything but Ive been trying different things all day with this and its getting frustrating. Has anyone has a similar experience? All console firebug results seem fine - as in all the query parameters are being passed over properely etc...