Hi.
If you have edited forumbits.css in CSS Templates
then You might wanna take a look at it.
When you open forumbits.css then you should see this.
make sure the code at red is set more then 0px.
By default its 8px.
Code:
.forumhead {
background: {vb:stylevar forumhead_background};
_background-image: none;
padding: 0;
font:{vb:stylevar forumhead_font};
color:{vb:stylevar forumhead_color};
clear:both;
margin-top: 8px;
float: {vb:stylevar left};
border: {vb:stylevar forumhead_border};
width: 100%;
-moz-border-radius-top{vb:stylevar right}: {vb:stylevar forumhead_top_corner_radius};
-moz-border-radius-top{vb:stylevar left}: {vb:stylevar forumhead_top_corner_radius};
-webkit-border-top-{vb:stylevar right}-radius: {vb:stylevar forumhead_top_corner_radius};
-webkit-border-top-{vb:stylevar left}-radius: {vb:stylevar forumhead_top_corner_radius};
border-top-{vb:stylevar right}-radius: {vb:stylevar forumhead_top_corner_radius};
border-top-{vb:stylevar left}-radius: {vb:stylevar forumhead_top_corner_radius};
}