O.k. here’s an update on the problem.
Using the_author() tag WITHIN the loop will not display the author on the front end. If the author is logged in, they will see his/her name displayed correctly on the front end (e.g. posted by [name here]) while they are logged in.
No author information is displayed either on the main index or single post (and yes, it is used within the loop)
For example, the following code will only display a zero ('0'):
<?php the_author_meta('user_email'); ?>
<?php the_author_meta('user_login'); ?>
<?php the_author_meta('user_pass'); ?>
<?php the_author_meta('user_nicename'); ?>
<?php the_author_meta('user_email'); ?>
<?php the_author_meta('user_url'); ?>
<?php the_author_meta('user_registered'); ?>
<?php the_author_meta('user_activation_key'); ?>
<?php the_author_meta('user_status'); ?>
<?php the_author_meta('display_name'); ?>
<?php the_author_meta('nickname'); ?>
<?php the_author_meta('first_name'); ?>
<?php the_author_meta('last_name'); ?>
<?php the_author_meta('description'); ?>
<?php the_author_meta('jabber'); ?>
<?php the_author_meta('aim'); ?>
<?php the_author_meta('yim'); ?>
<?php the_author_meta('user_level'); ?>
<?php the_author_meta('user_firstname'); ?>
<?php the_author_meta('user_lastname'); ?>
<?php the_author_meta('user_description'); ?>
<?php the_author_meta('rich_editing'); ?>
<?php the_author_meta('comment_shortcuts'); ?>
<?php the_author_meta('admin_color'); ?>
<?php the_author_meta('plugins_per_page'); ?>
<?php the_author_meta('plugins_last_view'); ?>
<?php the_author_meta('ID'); ?>
All authors are displayed correctly on the back end.
All authors have ALL their information filled out (including display name publicly as..) and has been confirmed by looking @ database entries.
I believe the problem is theme specific, as blog behaves normally with alternate theme; this being the case, what (possibly) within a theme’s code could cause this sort of problem?