Apparently if a user signs up for an account with only numbers in it
the system will not allow their profile to be shown because it will
search for the number as a user ID.
Actually it's just the number profiles. Go to any other profile on the site and you can see them fine as a guest. Its only the profiles with numbers only in the usernames.
Provide me FTP and Cpanel accesses to your site, because your site has specific mod which block non-members to view profiles.
Regards