Link username in comments to forum profile

Yes, with a simple template modification:

news_story_comment_profile

Code:

 <!-- Template: news_story_comment_profile -->
<a href="http://url_to_your_forum/member.php?action=profile&amp;id={$insert['newscomment_authorid']}">{$insert['newscomment_author']}</a>

You need to replace url_to_your_forum with the location of your forum

Look like index.php?showuser= is used in the current version of IPB, but the old way should also work. Did you also replaced http://url_to_your_forum with the full path of your IPB installation? E.g. http://yourdomain/board/

Code:

<!-- Template: news_story_comment_profile -->
<a href="http://url_to_your_forum/index.php?showuser={$insert['newscomment_authorid']}">{$insert['newscomment_author']}</a>