Hi Glenn, there are a lot of changes going from 1.3.2 to 2.0.4. One of the first things I would suggest is to look over any overrides you had setup before (template files placed in an ‘events’ folder) and merge any changes that were made in 1.3.2 with the new core template files in 2.0.4
Regarding categories specifically there were big changes with the way events are input (they are now custom post types) and categories are taxonomies. So my guess is you’re going to need to make some updates to this too to account for us using taxonomies vs. actual categories.
To get a category gridview you would go to http://www.yourdomain.com/calendar/category/your_category_name/
In general it would help to see your website or a screenshot or something, otherwise it’s hard to see what I’m working with 🙂
Does that help?