I have noticed that my quote form on my site is no longer working properly in firefox. The form is a self hosted PHP form displayed in an Iframe. This use to work but I have not checked it in a long time and have been wondering why quote request have been coming through email and not from the form. The Iframe does not show up in firefox.

https://www.p-s-s.com/quote%20request.htm

I can get the form to display in Windows Explorer if I acknowledge a window to display none secure data. My site is running as a HTTPS site.

Originally when I made the site it was standard HTTP site then late converted to HTTPS. do you guys think that the HTTPS could be causing my problems for displaying?

Any ideas on what to check?

Thanks
Ray