I am using aMember with the Authorize.net AIM plugin. It was working fine, but now it was pointed out that the checkout page is not forcing HTTPS. In fact, I was viewing the site with HTTPS and when I went to the payment page, it was switched to just HTTP. I cannot find a setting anywhere to tell it to force HTTPS. I have created my own membership forms and place the pay systems at the bottom of the page. When I hit submit it actually switches from HTTPS to HTTP. I am using version 4.5.3 of aMember. I know there is an upgrade and will be doing that soon.
I figured it out, the secure URL for my site for some reason no longer had the https on it. Since you have to click on the "change" link under the global settings it took me awhile to find this.