All width and Height of iframes in my site are getting overriden

Hi,

I need some help please. All widths and heights of my iframes in my site are getting overridden. I have a had a good look on firebug and can not spot what's going on. I have disabled all plugins to see if the css is coming from there but it does not seem that is the case. Can i get some help please?.

e.g http://thundermaps.com/contact/