Restricting a search to the actual story

Given that the Category Browser still doesn't permit AND type searches I've been using the search box.

However, I've been getting what seemed to be a bunch of false returns. Stories which didn't contain the words that I had searched for. After a little playing around, I realised that when searching it's also including the comments.

Not only that ... I'm getting returns for forums posts and blog entries.

How do I restrict a search to a particular type of entry, be it story, blog or forum post? And how do I restrict the search so that it doesn't include comments on stories?