using privatemsg_new_thread() inside an action - 2 problems

Hi,

I'm writing an action for a module, and using the privatemsg api. I'm experiencing two problems.

1: Cannot set author
The following code works, and sends a message from "Guest":

  privatemsg_new_thread(user_load($uid), $subject, $body);

However, the following code doesn't work:

  privatemsg_new_thread(user_load($uid), $subject, $body, array('author'=>user_load(1)));

This doesn't send a message at all.

Alternatively,

  privatemsg_new_thread(user_load($uid), $subject, $body, array('author'=>$object));

does send a message, but still from "Guest," not the user identified in the array.

2: no e-mail notification
Even when I don't set the author and the message gets through, e-mail notification is not triggered. Is there a separate function for this, or is this a bug?

Any pointers in the right direction would be greatly appreciated!

cheers