CSS related posts title issue

Hi, sorry to bother you with a dumb question. Ever since I upgraded to the latest version, the CSS for the title of my related posts section (YOU MIGHT ALSO LIKE:) has been messed up. No matter what I try, I can’t make the title go from italic to normal and from 17 point font size to 12 point. Can you please tell me what I’m doing wrong? I have tried inserting each of the following sections of code in my custom css area, nothing works.

.related_post_title h3 {
clear: both;
font-family:Helvetica, sans-serif;
font-size:12px !important;
font-style:normal !important;
padding: 0 !important;
margin: 0 !important;
}

.related_post_title {
clear: both;
font-family:Helvetica, sans-serif;
font-size:12px !important;
font-style:normal !important;
padding: 0 !important;
margin: 0 !important;
}

http://wordpress.org/extend/plugins/wordpress-23-related-posts-plugin/