I’m trying to create an archive mapping but can’t seem to find out how to get it so that it will only create a file for that category if it’s a primary category and not a sub-category.
For example, I have this category list:
Category 1 - north - south Category 2 - west - north Category 3 - south
I want to create this file: http://www.mysite.com/category1/index.php but it also creates: http://www.mysite.com/north/index.php
Any idea how I can avoid subcategory files to be created from that template?

The category list doesn't appear the way I typed it :S. Everything listed there is a category. The ones with dashes are sub-categories.
Try wrapping the entire category archive with a HasNoParentCategory tag: http://www.movabletype.org/documentation/appendices/tags/hasnoparentcategory.html
Hmm, this work inside the template. It just outputs empty files. Thanks for the tip though, it will be usefull on other situations. I don't think I'll find a way for those subcategories to not output files :(
What I did to solve this temporarily is set the templates to dynamic publishing. This way no actual files are created for any category/subcategory and only called if needed. I would still like to solve this for static publishing though.. would prove really useful.
I don't know if you're comfortable with doing a little bit of Perl coding, but here is a possible way of doing that with a simple plugin. Based on this: http://www.movabletype.org/documentation/man/MT/WeblogPublisher.html#CALLBACKS
Create a plugin that adds a callback to BuildFileFilter that checks the current category, and if it has a parent category, return false.
Give this a shot and tell me how it works for you.
Oh this seems exactly what I need. I'll update to 4.23 first and then try it out! Thanks for the link :)
I believe it works! Thanks Mike! :D