Hi,
I just wanted to share with you a small hack to get the plugin working on a current category only instead of category exclusion.
Published on my blog, here is the « hack » : http://blog.eexit.net/2012/04/php-wordpress-popular-posts-for-the-current-category.html
Hope this will be helpful =)
http://wordpress.org/extend/plugins/wordpress-popular-posts/