New install From Address override not working

I have deployed the smtp module and no matter if I have an "E-mail address:" set in the Site configuration page or the "E-mail from:" in the E-mail optiones section of the SMTP support page, the From address in the e-mail is always that of the particular user sending the messages from the Contact page or of the user sending a PM (for notification).

I use SMTP authentication and the address I am attempting to use as the From address is authorized to send by the ISP. I am able to send a test message from the SMTP Support page and it works perfectly, just not from the rest of the site e-mail functions.

I have even attempted to hard code the "$from" address in various places of the smtp.module but all attempts to do so have failed.

I have the Site's E-mail address and the SMTP Support From E-mail address both set to noreply@mydomain.org. When I send a message on the contact page to a user I get errors:

"Error sending e-mail from admin@mydomain.org to myaddress@mydomain.org: The following From address failed: admin@mydomain.org"

As you see the from address is not being determined by the site or the SMTP from address, it is using the admin's address.

smtp-5.x-1.0
Drupal 5.16
PHP 5.2.6

Help?