Search error when using SharePoint 2013 in an iFrame. IE only

Hi all.

I have SharePoint 2013 running in an iFramed window.  When I try to use the search function, I get a javascript "Access Denied" error.  This only happens when using IE.  I can use Chrome and it works fine.

I thought this to be a cross domain issue, but both the iFrame page and the SharePoint 2013 site live on the same domain. For example:

iFramed page address is https://site1.mydomain.com and SharePoint 2013 is on https://site2.mydomain.com.  I tried to monkey with the trusted zones and intranet sites in IE security and I even allowed the "Send data across domains" option to be enabled in IE, but still nothing.

Strange that it works in Chrome and not IE.  Anyone had the same experience?

Thanks

Phillip