RSS links are off site links that need to open in a new page - or you will be sending people OFF YOUR site to some other site - not what most administrators want to do.

inc/design.inc.php

find:

Code:
<a href="<?= $oItem -> link ?>"><?= htmlspecialchars_adv( $oItem -> title ) ?></a>
change to:

Code:
<a href="<?= $oItem -> link ?>" target="_blank"><?= htmlspecialchars_adv( $oItem -> title ) ?></a>
and find

Code:
<a href="<?= $oRSS -> link ?>"><?= _t( '_Visit Source' ) ?></a>
change to

Code:
<a href="<?= $oRSS -> link ?>" target="_blank"><?= _t( '_Visit Source' ) ?></a>

In the admin panel - for you, the administrator, so you don't get sent off your admin panel:

find in admin/index.php

Code:
<div class="news_title"><a href="<?=$oItem -> link?>"><?=$oItem -> title?></a></div>
change to

Code:
<div class="news_title"><a href="<?=$oItem -> link?>" target="_blank"><?=$oItem -> title?></a></div>