AdminCP > Styles and Templates > Style Manager > Navigation / Breadcrumb Templates > Navbar > and find this code.....
PHP Code:
<if condition="$show['forumdesc']">
<table class="tborder" cellpadding="$stylevar[cellpadding]" cellspacing="$stylevar[cellspacing]" border="0" width="100%" align="center">
Above that code you should see a tag that looks like....
Delete that and you should be good to go. Hope that helps