Viewing all posts within a category

Hi Guys

Since the last update the categories don't filter to their own posts, i use the category list view (i use a few sub-categories) but it doesn't matter which Category i click on it always takes me to the main list which shows all post linked to the main categories only.

in the old days when i clicked on a sub cat it would only show posts belonging to that sub category

this doesn't work even if you click on the category whilst reading the full blog post

Please advise

thanks
Wayne