IE quirk with iFrame and position: relative

I have a project I have been working on that involves promoting realtor properties to multiple listing sources such a google, trulia and others. On one site in particular my client had noticed that there was as an issue where the property page form his web site would not show inside an iframe on the the listing web site using IE. I managed to trace it down to a style sheet issue. For some reason, cannot remember, I had put the css attribute ‘position: relative’ on the body and html elements. This passed the WC3 validator, but IE didn’t like this so the page would not show at all inside the iframe. Removing the attribute solved the problem.

Note: this was not error with FireFox.