Hi there. I just noticed tags in comments are not auto-closed, so when someone uses
<em> in a comment but doesn't close it, the rest of the page is printed in bold and/or italics. I don't know if this is a general WordPress-issue or if it's only an issue with some themes.
/edit: Not only does it do this when viewing the post, but also when managing comments in the admin-area, so it can't be a theme-issue. That's not surprising; I think it would be good if tags in comments were auto-closed.