I ran into a situation where user created a discussion board with "categories" and they have views created to display the respective categories. So far so good. BUT seems like when a user responds to a discussion (on a flat view[/flat.aspx page]) it does not pick the "category". So when people go to any particular view it shows the discussion and the number of replies (see below). Once you click the discussion to see the replies - it's empty. With a bit of digging (editing the reply) I noticed "reply" does not store the Category information - hence being filtered out.
If I create a new view without any Filter, replies can be seen. Is this behaviour normal? if so what's the point of creating "categories"? I see people create Categories quite often. Here is an example of adding Categories to a discussion board. 2nd one here.
Any feedback would be greatly appreciated!