Call to undefined function: array_fill_keys()

Hmm, it looks like you're using an older version of PHP, lower than version 5.

There are several ways to go here:

1. You can ask your host to upgrade to PHP 5 - see the note below.
2. I can try to add a replacement function.
3. I can just say that PHP 5 is a requirement (and add a hook_requirements).

NOTE: Drupal 6 already requires at least PHP 5. Drupal 7 will require 5.2+. I strongly recommend that you get your host to upgrade now, or find a new host.

That's not necessarily the way I want to go; it's not currently a D5 requirement (although I wish it were).. And if I do that, then I need to add a hook_requirements to the module.

Actually, I gave you some incorrect information. Drupal 6 only requires PHP 4.3.5.

And, in looking at all this, I found a much better way to fix the problem. I will commit a fix, but in the meantime, remove the array_fill_keys, and replace it with just "array()".

Fix committed on both branches.