Submit forms on secure connection

[eluser]Unknown[/eluser]
I have a registration page that uses a secure connection so the URL is https://example.com/join/

I have a log in form and a registration form on that page but for some reason when I submit those forms the post values are always empty. I've made sure the methods that the forms submit to have a secure connection URL but for some reason the forms aren't submitting properly. Has anyone else had a similar problem?

Thanks for any help.