Index: /CKEditor/branches/versions/3.5.x/_source/plugins/maximize/plugin.js
===================================================================
--- /CKEditor/branches/versions/3.5.x/_source/plugins/maximize/plugin.js	(revision 6223)
+++ /CKEditor/branches/versions/3.5.x/_source/plugins/maximize/plugin.js	(revision 6224)
@@ -199,23 +199,13 @@
 								{
 									overflow : 'hidden',
-									width : ( CKEDITOR.env.opera ? viewPaneSize.width : 0 ) + 'px',
-									height : ( CKEDITOR.env.opera ? viewPaneSize.height - 16 : 0 ) + 'px'
+									width : 0,
+									height : 0
 								};
 
-							if ( CKEDITOR.env.ie )
-							{
-								mainDocument.$.documentElement.style.overflow =
-									mainDocument.getBody().$.style.overflow = 'hidden';
-							}
-							else
-							{
-								// Prevent window scrolling, e.g. focus moving outside the editor. (#6747)
-								mainDocument.getDocumentElement().setStyle( 'overflow', 'hidden' );
-								mainDocument.getBody().setStyles( styles );
-							}
-
-							// #4023: [Opera] Maximize plugin
-							if ( CKEDITOR.env.opera )
-								mainDocument.getBody().getParent().setStyles( styles );
+							mainDocument.getDocumentElement().setStyles( styles );
+							// The fixed position is needed for preventing window scrolls by mouse wheel or focus switch,
+							// even if the scrollbars are not shown (#6747).
+							!CKEDITOR.env.gecko && mainDocument.getDocumentElement().setStyle( 'position', 'fixed' );
+							mainDocument.getBody().setStyles( styles );
 
 							// Scroll to the top left (IE needs some time for it - #4923).