Cannot add feedback in iframe on webshop site

I am in the process of switching sites from my normal site www.lan-inn.eu where the forums work without problems to my new site in development at the moment http://testshop.lan-inn.eu. The problem I have is the forum does not work in the test site. when I try to enter new feedback the page greys out and there are no options or text boxes too fill. The old site uses HTML but the new shop site uses PHP the iframe in the shop site is. It appears that popups are not working within the frame. I would appreciate any help with this as its a show stopper for the new site if I cannot integrate it into the site.