Fatal error: Cannot redeclare signup_reminder_sql()

It's repeatable on my 5.2 site by using the admin/logs/status/run-cron link found on the admin/logs/status page. All systems are green, all modules are up-2-date, and db schema is fine. More info as I have it.

I cannot figure out why it's making this error. Somebody ask me a question and I'll troubleshoot the answer for you.

Patch attached, thanks to killes' good eye. I hope this is right?

The patch I attached only addresses the first line of code, but the entire function has three more include() statements in it. Here, look for yourself:

function _signup_initialize_event_backend() {
  define('SIGNUP_PATH', drupal_get_path('module', 'signup'));
  if (defined('EVENT_API') && EVENT_API == '5.2') {
    include_once(SIGNUP_PATH .'/signup_event_5.x-2.inc');
  }
  else if (module_exists('event')) {
    include(SIGNUP_PATH .'/signup_event_5.x-1.inc');
  }
  else if (module_exists('date')) {
    // include(SIGNUP_PATH .'/signup_date.inc');
    // Until date.module support exists, fall back to the no event case.
    include(SIGNUP_PATH .'/signup_event_none.inc');
  }
  else {
    include(SIGNUP_PATH .'/signup_event_none.inc');
  }
}

Should I change those to include_once() as well?

Following up to my own follow-up.

Changing all the lines from include() to include_once() doesn't fix the fatal error that is triggered during a manual cron run. Site is D5.2, and module is 5.x.2-2. Also using Event 5.x-1.0.

The first patch was wrong. Don't use it. This is the correct one. it was an include_once, but not the one I suspected.