Pingbacks

I’ve never really cared about this, so I don’t know what it really does either, but I recently posted an entry with a link to an older entry of my blog. Then I got a mail that I got a pingback on my post. Anyway, the thing is that somehow it makes the pingback as a comment on that earlier post, and screws with the layout of my site. Is there a place to fix this? The comment has the codes < pre > and < code >, what is that?