importNode for web-page document in another domain

Question

I want to get at the 'outerHTML' of a node I've captured using document.evaluate (ie xPath) from a node on another web page that is from a different domain. I.e. I have a Firefox tab running my javascript that is trying to access the content of a second tab. I dont have control over the content of the web page in the second tab.

I used importNode along with the answer to a similar question...

How do I do OuterHTML in firefox?

I am able to do other cross domain manipulation, but cant get importNode to work. I only need this to work in Firefox.

This is where I've got to so far - get error message: "Access to property denied code: 1010" ...

netscape.security.PrivilegeManager.enablePrivilege("UniversalBrowserRead");
netscape.security.PrivilegeManager.enablePrivilege("UniversalBrowserWrite");
netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");

var recordNodeClone = currentFrame.document.importNode(recordNode, true);

var fosterParentNode = document.createElement('div');

//Error for line below: Access to property denied" code: "1010
fosterParentNode.appendChild( recordNodeClone );

var recordNodeOuterHTML = fosterParentNode.innerHTML;

console.log("fosterParentNode=%o", fosterParentNode);
console.log("fosterParentNode.innerHTML=%o", fosterParentNode.innerHTML);