The WordPress URL settings are correct.
I have narrowed down the problem to these two pages generated by the Newsletter PHP.
http://morganhillphotographyclub.org/wp-content/plugins/newsletter/subscription/page.php?nm=profile&nk=35-606f2bc001 [Note: Profile page with "click here" hyperlink]
http://morganhillphotographyclub.org/wp-content/plugins/newsletter/subscription/page.php?nm=unsubscription&nk=35-606f2bc001 [Note: Un-subscription page generated from the Welcome email with "clicking here" hyperlink]
For some reason the newsletter PHP is generating the incorrect URL for the “click here” or “clicking here” hyperlinks on these two pages.
The incorrect hyperlink that these pages are generating is:
<a href="http://gwzdesign.net/MHPC-WP/http://morganhillphotographyclub.org/wp-content/plugins/newsletter/do/unsubscribe.php?nk=35-606f2bc001">click here</a>
The correct hyperlink should be:
<a href="http://morganhillphotographyclub.org/wp-content/plugins/newsletter/do/unsubscribe.php?nk=35-606f2bc001">click here</a>
Clicking on the unsubscribe link in a Newsletter email does not generate the error and all the other pages are working correctly and have the correct hyperlinks.
George