With a recent upgrade of HTTPS (3.1 and in 3.2) something broke with respect to a opt-in web form that links to a SSL based URL.
My page is in HTTP mode, but when we process the opt-in form code we post to a SSL page and then it breaks with an error on the destination page.
Here is an example of the opt-in form error with WordPress HTTPS v3.2 is active. Simply enter in some data into the form and submit it.
Here is the same WP site and opt-in form without WordPress HTTPS v3.2 active:
Both sites are almost identical with the only exception being data, but the WP version and plug-ins are the same.