pagenation not working when excluding category

sorry if this question had been answered. i searched the forums and couldn’t find a solution that worked with this specific problem.

https://www.plasmodium.net/category/music/

this category is the archive.php listing category 12 (music) minus category 8 (podcast). since podcast has it’s own listing these entries are non-podcast music posts. pagenation works fine for all other categories, so this exclusion is most likely the culprit.

exclusion code

<?php if ( is_category('12') ) { query_posts('cat=12,-8'); } ?>

pagenation code

<div id="blog-list-more">
    <div class="next"><?php previous_posts_link('&nbsp;'); ?></div>
    <div class="previous"><?php next_posts_link('&nbsp;'); ?></div>
</div>

help is greatly appreciated.