Pagination on my site is broken

I recently installed the pagination plugin called WP-Paginate. I have got the pagination links to sppear under my posts by using this code:

<?php if(function_exists('wp_paginate'))
		wp_paginate(); ?>

Everything seems to work fine, but the pagination is a bit broken.

For example, when I’m displaying all my posts from a single category (in this case lets call the category “skins”) this is my URL:

https://somesite.com/wp/skins

When I go to page two using the pagination plugin this is the new URL:

https://somesite.com/wp/skins/page/2

but it isn’t displaying any posts. It seems to be displaying index.php based on the template hierarchy. How can I stop this and make it show page 2 of the skins category?

Thanks, and if you need me to explain anything else then let me know ??