Edit comments not working

One of my readers posted non-valid html in his comment, so I decided to edit it – only to find out that something’s broken.

When I choose the comment to edit I get the ‘edit comment’ page no problem. When I’m finished and press the ‘edit comment’ button, it goes into post.php, puts the comment’s text into the post field… as if I was using that text to make a post. The comment remains unchanged.

What’s going on with that? I don’t think I’ve done anything to my site that could have broken the admin pages…….