Hey, thanks in advance for the help. The error I get is:
Parse error: syntax error, unexpected $end in /home/shaneall/public_html/forum/viewtopic.php on line 186
and here's the code snippet:
177: <?php
178:
179:
180: require PUN_ROOT.'include/parser.php';
181:
182: $bg_switch = true; // Used for switching background color in posts
183: $post_count = 0; // Keep track of post numbers
184:
185: // Retrieve the posts (and their respective poster/online status)
186: $result = $db->query('SELECT u.email, u.title, u.url, u.location, u.use_avatar, u.signature, u.email_setting, u.num_posts, u.registered, u.admin_note, p.id, p.poster AS username, p.poster_id, p.poster_ip, p.poster_email, p.message, p.hide_smilies, p.posted, p.edited, p.edited_by, g.g_id, g.g_user_title, o.user_id AS is_online FROM '.$db->prefix.'posts AS p INNER JOIN '.$db->prefix.'users AS u ON u.id=p.poster_id INNER JOIN '.$db->prefix.'groups AS g ON g.g_id=u.group_id LEFT JOINI've checked everything I can think of, but my programming skills aren't very high, plus it was C++, not PHP! 
UPDATE: I went and compared the viewtopic.php installed on my server to the one that came with the installation, and discovered that I was missing 10 KB of code!!! Needless to say, I think that was the problem. 
How it happened, IDK, but I copied the complete viewtopic.php into my forum directory, and now it all works great. Thanks anyway!