Weird: suddenly, whenever I load up my blog, the name of every single category is displayed across the top in the space which is either blank (when looking at the default blog page) or has a category name or post title there (when viewing one category or one post). You know the bit I mean, right?

Looked fine earlier today... I've not made any changes I can think of that would affect that, and certainly nothing to that piece of code. What's going on, and why is it doing it?

It's the standard code that looks like this:

<h2><?php
	single_cat_title();
	single_month_title();
	single_post_title();
	arcdir_title();
	last_comments_title();
	stats_title();
	profile_title();
?></h2>