Hi, after a bit of fiddling I've managed to get the headlines for posts to what I want - but now I get these fat, screaming headlines in the comments-area instead... Where did I miss to change this, I can't seem to find this particular one...

//Jenny

You could use the following in CSS Inserts styling the font any way you wish.

h3#comments {
font-size:18px;
}

Hi and thanks - that took care of the headline for existing comments, but not the one in the actual comment-form... I suppose it should be the same insert although with a different specification than "comments"... or am I thinking entirely wrong here? Help! And big thanks in advance!

//Jenny

That selector would be

h3.reply {
font-size:18px;
}

If you use Firefox you can get the Firebug extension which is all I use to find selectors. Great tool.