Index: /CKEditor/trunk/_source/plugins/wysiwygarea/plugin.js
===================================================================
--- /CKEditor/trunk/_source/plugins/wysiwygarea/plugin.js	(revision 5991)
+++ /CKEditor/trunk/_source/plugins/wysiwygarea/plugin.js	(revision 5992)
@@ -556,6 +556,4 @@
 						if ( CKEDITOR.env.gecko )
 						{
-							// Set the HTML style to 100% to have the text cursor in affect (#6341)
-							domDocument.getDocumentElement().setStyle( 'height', '100%' );
 							domDocument.on( 'mouseup', function( ev )
 							{
@@ -980,5 +978,5 @@
 			// Setting voice label as window title, backup the original one
 			// and restore it before running into use.
-			editor.on( 'contentDom', function ()
+			editor.on( 'contentDom', function()
 				{
 					var title = editor.document.getElementsByTag( 'title' ).getItem( 0 );
@@ -998,4 +996,7 @@
 				editor.addCss( selectors.join( ',' ) + '{ display:inline-block;}' );
 			}
+			// Set the HTML style to 100% to have the text cursor in affect (#6341)
+			else if ( CKEDITOR.env.gecko )
+				editor.addCss( 'html { height: 100% !important; }' );
 
 			// Switch on design mode for a short while and close it after then.
@@ -1006,5 +1007,5 @@
 					{
 						editor.document.$.designMode = 'on';
-						setTimeout( function ()
+						setTimeout( function()
 						{
 							editor.document.$.designMode = 'off';