Index: branches/5.2.x/core/admin_templates/js/script.js
===================================================================
diff -u -N -r15371 -r15372
--- branches/5.2.x/core/admin_templates/js/script.js	(.../script.js)	(revision 15371)
+++ branches/5.2.x/core/admin_templates/js/script.js	(.../script.js)	(revision 15372)
@@ -1391,19 +1391,21 @@
 	// 1. cycle through popups to get main window
 	try {
 		// will be error, when other site is opened in parent window
-		var $i = 0;
-		var $opener;
+		var $i = 0,
+			$opener,
+			$is_frameset = false;
 
 		do {
-			if ( $i == 10 ) {
+			if ( $i == 10 || $is_frameset ) {
 				break;
 			}
 
-			// get popup opener
+			// try to get popup window opener
 			$opener = $main_window.opener;
 
 			if ( !$opener ) {
-				// when no opener found, then try parent window
+				// not inside a popup, then we're inside a frameset already - get it once
+				$is_frameset = true;
 				$opener = $main_window.parent;
 			}
 
@@ -1415,8 +1417,9 @@
 		} while ($opener);
 	}
 	catch (err) {
-		// catch Access/Permission Denied error
-//			alert('getFrame.Error: [' + err.description + ']');
+//		catch Access/Permission Denied error
+//		alert('getFrame.Error: [' + err.description + ']');
+
 		return window;
 	}