BuddyPress.org

In ur themes function.php (create one if it doesn’t exist in ur theme folder) add

<br />

/* Register an additional fourth widget column */<br />

register_sidebars( 1,<br />

array(<br />

'name' => 'fourth-section',<br />

'before_widget' => '<div id="%1$s" class="widget %2$s">',<br />

'after_widget' => '</div>',<br />

'before_title' => '<h2 class="widgettitle">',<br />

'after_title' => '</h2>'<br />

)<br />

);<br />

and alter the code in ur post above to

<div id="fourth-section" class="widget-section"><br />

<?php if ( !function_exists('dynamic_sidebar')<br />

|| !dynamic_sidebar('fourth-section') ) : ?></p>

<p>    <div class="widget-error"><br />

<?php _e( 'Please log in and add widgets to this section.', 'buddypress' ) ?> /wp-admin/widgets.php?s=&show=&sidebar=first-section"><?php _e( 'Add Widgets', 'buddypress' ) ?><br />

</div></p>

<p>    <?php endif; ?></p>

<p>    </div>

This should bring u a functional fourth-section sidebar in the wordpress backend. Valid for BP 1.1.3 Theme.