use it in two sites already, because sometimes somehow people get a link to the category archive looking like this: mysite/categoryname/
Wordpress is using archive.php, but the offered link to mysite/categoryname/page/2/ gives a 404 error.
Actually categories link looks like: mysite/category/categoryname/ - I know this.
Anyway, this plugin does a good job on these wrongly displayed category archives by making pagination work.
May I suggest to add /category/ in the link structure of redirected 404s, so the user will come to the correct structure on page 2 and following