Cannot verify the identity of page

I have the Paypal Pro plugin installed and the form works well. (transaction works)

The problem I'm having is with the site certificate (At least I think that is the problem). The site I'm working on is a sub domain. When I try to launch the page I get a nasty warning through Chrome that this page may be malicious. Safari is a bit nicer saying that it "cannot verify server identity"

Do I need to move to a new and separate server or is there a work around.

P.S. I'm already using an SSL certificate on another sub domain and Media Temple will not allow two SSL certificates. I can get a third party SSL but that just complicates matters for a simple donate button and form.

The donation page : http://wp.me/P29bpg-2At

Answer: http://gravityhelp.com/documentation/page/PayPal_Payments_Pro_Add-On
The Gravity Forms PayPal Payments Pro Add-On requires the use of the Pricing Fields in Gravity Forms v1.6.3+ and will not work with older versions of Gravity Forms.

Because of the secure nature of capturing credit card information you will also be required to purchase and install an SSL certificate on your web site. You will also need to configure your WordPress site to work properly with SSL.

Contact your web host if you need assistance purchasing and configuring an SSL certificate.

If you need assistance configuring your WordPress site to work with SSL we recommend the WordPress HTTPS (SSL) Plugin which you can find here:

http://wordpress.org/extend/plugins/wordpress-https/