IFRAME w/ SSL

Hi – I have the following scenario – Page served over https:// with an iframe using an https:// SRC attrib.

Example is here http://www.talkforgood.com/checkout-page40/

I would like this to be https://www.talkforgood.com/checkout-page40/

When WP HTTPS plugin is enabled the src in the IFRAME is being re-written with http rather than https.

How can I fix this?

Thanks,
Graham

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