Opera 12.0 still implements an older version of the DOM so cloneNode cannot be...

Opera 12.0 still implements an older version of the DOM so cloneNode cannot be called without an argument

src/support.js

@@ -139,7 +139,7 @@ jQuery.support = (function() {
 	}
 
 	div.style.backgroundClip = "content-box";
-	div.cloneNode().style.backgroundClip = "";
+	div.cloneNode( true ).style.backgroundClip = "";
 	support.clearCloneStyle = div.style.backgroundClip === "content-box";
 
 	// Run tests that need a body at doc ready