Drupal Breaks On Multiple Module Directories With Same Module

Drupal breaks, giving white screen only, when you place the same module in multiple directories. For example, if I were to place the cck module into /drupal/modules, though not recommended, and lets say I forgot I placed it there and then I put cck module into /drupal/sites/all/modules, a better place for modules. So after I do that I can go into drupal and go to the modules section, see cck, but once I select and enable it and submit the page all I get is a white page. I would think the behavior should either report a visual error, default and only load one version, or something. This bug probably would not be encountered too often but I do believe it is a bug. I am running on MacOS 10.4.8 PPC, the rest of my system profile is as followed.

Drupal 5.1
Configuration file Protected
Cron maintenance tasks Last run 5 days 47 min ago
You can run cron manually.
Database schema Up to date
File system Writable (public download method)
MySQL database 5.0.19
PHP 5.1.2
Unicode library PHP Mbstring Extension
Web server Apache/2.0.55 (Unix) PHP/5.1.2 DAV/2 mod_ssl/2.0.55 OpenSSL/0.9.7l

Thanks,
-mpare
www.paretech.com