Send signups to:

file:
signup.module

line 750

    case 'load':
      // Check for a signup for this node.
      // If it's a new node, load the defaults.
      $result = db_query("SELECT * FROM {signup} WHERE nid = %d", ($node->nid ? $node->nid : 0));

Looking at my database only node->id = 0 is ever changed when in

http://localhost:85/childcck/?q=admin/settings/signup

So the query should query against node->id = 0.

Also would be nice to be able to send signups to node owners.

As a result no notifications are ever sent.