Can't enable taxonomy_access module

Hi, I've installed taxonomy_access (4.7.0) on Drupal 4.6.4, I've enabled it under modules, then I go into Admin->settings->taxonomy_access and I can't enable it from here:

The module is currently disabled, but must also be disabled in the modules admin page in order for it to be properly disabled.
To properly enable this module, select 'enable' here and save the configuration.

But beside the "Submit" button, there is no "enable" option, it just says "Array".

This is under PHP5