iframe wrapper not working

Trying to make an iframe wrapper in a page. The link I am using is http://www.loopnet.com/profile/1246096221/Zachary-Miller/Listings/

It gives me this error: Unable to resolve the server’s DNS address.

I works if I just use an address with .com at the end. Not sure what I am doing wrong.

Website page trying to load to: http://allurecolorado.com/commercial-listings/

Thanks for the help.

http://wordpress.org/plugins/iframe-wrapper/