diff --git a/wp-includes/js/wp-auth-check.js b/wp-includes/js/wp-auth-check.js
index 2a1731879b..aa2b1ddcb0 100644
--- a/wp-includes/js/wp-auth-check.js
+++ b/wp-includes/js/wp-auth-check.js
@@ -1,6 +1,6 @@
 // Interim login dialog
 (function($){
-	var wrap, check, scheduleTimeout, hideTimeout;
+	var wrap, check, scheduleTimeout;
 
 	function show() {
 		var parent = $('#wp-auth-check'), form = $('#wp-auth-check-form'), noframe = wrap.find('.wp-auth-fallback-expired'), frame, loaded = false;
@@ -22,20 +22,23 @@
 					height = body.height();
 				} catch(e) {
 					wrap.addClass('fallback');
+					parent.css( 'max-height', '' );
 					form.remove();
 					noframe.focus();
 					return;
 				}
 
 				if ( height ) {
-					if ( body && body.hasClass('interim-login-success') ) {
-						height += 35;
-						parent.find('.wp-auth-check-close').show();
-						wrap.data('logged-in', 1);
-						hideTimeout = setTimeout( function() { hide(); }, 3000 );
-					}
-
-					parent.css( 'max-height', height + 60 + 'px' );
+					if ( body && body.hasClass('interim-login-success') )
+						hide();
+					else
+						parent.css( 'max-height', height + 60 + 'px' );
+				} else if ( ! body || ! body.length ) {
+					// Catch "silent" iframe origin exceptions in WebKit after another page is loaded in the iframe
+					wrap.addClass('fallback');
+					parent.css( 'max-height', '' );
+					form.remove();
+					noframe.focus();
 				}
 			}).attr( 'src', form.data('src') );
 
@@ -47,14 +50,14 @@
 		if ( frame ) {
 			frame.focus();
 			// WebKit doesn't throw an error if the iframe fails to load because of "X-Frame-Options: DENY" header.
-			// Wait for 5 sec. and switch to the fallback text.
+			// Wait for 10 sec. and switch to the fallback text.
 			setTimeout( function() {
 				if ( ! loaded ) {
 					wrap.addClass('fallback');
 					form.remove();
 					noframe.focus();
 				}
-			}, 5000 );
+			}, 10000 );
 		} else {
 			noframe.focus();
 		}
@@ -62,7 +65,6 @@
 
 	function hide() {
 		$(window).off( 'beforeunload.wp-auth-check' );
-		window.clearTimeout( hideTimeout );
 
 		// When on the Edit Post screen, speed up heartbeat after the user logs in to quickly refresh nonces
 		if ( typeof adminpage != 'undefined' && ( adminpage == 'post-php' || adminpage == 'post-new-php' )
@@ -89,12 +91,12 @@
 
 		if ( data['wp-auth-check'] && wrap.hasClass('hidden') ) {
 			show();
-		} else if ( ! data['wp-auth-check'] && ! wrap.hasClass('hidden') && ! wrap.data('logged-in') ) {
+		} else if ( ! data['wp-auth-check'] && ! wrap.hasClass('hidden') ) {
 			hide();
 		}
 	}).ready( function() {
 		schedule();
-		wrap = $('#wp-auth-check-wrap').data( 'logged-in', 0 );
+		wrap = $('#wp-auth-check-wrap');
 		wrap.find('.wp-auth-check-close').on( 'click', function(e) {
 			hide();
 		});