Check out this post:

http://babalublog.com/2009/02/great-...le-planetbarf/

Since the post has an extraordinarily long headline (intentional) it goes to two lines. The line spacing was kind of screwy so I added some line height formatting in Post/Page Styling area. But the problem persists on the bottom of the post where the headline is repeated for the comments section.

Where can adjust this?

You can access that other headline via HTML/CSS Inserts -> CSS Insert

h3#comments {
line-height: 1.5;
}