Right -- what Australis and Seedfork said. When you ask a question you get to pick the categories that fit. If you want to find just questions that match a certain category you need to find one that has that category and click on the green box at the bottom for the category. I also think that Dave intends to improve the ability to search for a category (or at least I hope so).
Philip, can you see the green category boxes (at the bottom of a posted question) when using your phone?
