OK I have done a pretty good (as far as I can tell) search for how to do this and can only find info on default sort order of sites within a category.

What I would like to know is how do I change the sort order of categories that display as a verticle list within a parent category.

For example, if you look here: http://www.fattymattybrewing.com/directory/695.html

all the categories under their parent categories are listed by, 1st to last the categories with the most sites in them are at the top...

How do I change this to make the child categories within a parent category show up alphabetically?