Embedding a Creator Form into a secure site (SSL)

Embedding a Creator Form into a secure site (SSL)

I have created a form in Creator, which I embed in an iFrame on a web page that has an SSL certificate.  On certain IE browsers I get an error loading the page stating that some elements may not be secure.  The only element on this page that isn't secure is the iFrame.
My hosting service had me check all the HTML that we could find,  looking for links in the iframe that referred to the unsecure (http:)  site address instead of the secure one (https:),  but we couldn't find any.

Is there a way to make the form in the iframe secure on an SSL certificate site?