Configuring phpBB block fails

Attempting to configure the phpBB Topics block under the admin/block page causes something in forms.inc to fail. I think that this may be related to a php5 change with array_shift(). I get an error message (on my test machine) something like the following:

array_shift() [function.array-shift]: The argument should be an array in /Library/WebServer/americaninventorspot/includes/form.inc on line 500.

My config: FreeBSD 6.1 i386, Drupal 4.7.6, php5.2.1, mysql 4.1.20
My website: American Inventor Spot

Solution: I decided to fix the block_block() hook in the phpbb.module to remove the error and allow me to configure the block using the default options. I also removed the empty code for more than one Forum Topics block since it wasn't implemented anyway. Here's my solution:

in phpbb.module line 231:
changed from:

function phpbb_block($op = 'list', $delta = 0, $edit = array() ) {
  if ($op == 'list') {
    $blocks[0]['info'] = t(variable_get('phpbb_block0_title', 'phpBB Topics'));
         return $blocks;
  }
  else {
    switch ($delta) {
      case 0:
                        $block['subject'] = t(variable_get('phpbb_block0_title', 'phpBB Topic\
s'));
                        $block['content'] = _phpbb_display_block_0();
      break;

      case 1:
                        //Not used
                break;
    }
         return $block;
  }
}

changed to:

function phpbb_block($op = 'list', $delta = 0, $edit = array() ) {
  switch ($op) {
    case 'list':
      $blocks[0]['info'] = t(variable_get('phpbb_block0_title', 'phpBB Topics'));
      return $blocks;
    case 'configure':
      $form = array();
      return $form;
    case 'save':
      // stub, no special data to save
      return;
    case 'view':  // fall through
    default:
      $block['subject'] = t(variable_get('phpbb_block0_title', 'phpBB Topics'));
      $block['content'] = _phpbb_display_block_0();
      return $block;
  }
}