Index: /CKEditor/trunk/_source/plugins/autogrow/plugin.js
===================================================================
--- /CKEditor/trunk/_source/plugins/autogrow/plugin.js	(revision 7031)
+++ /CKEditor/trunk/_source/plugins/autogrow/plugin.js	(revision 7032)
@@ -8,4 +8,42 @@
  */
 (function(){
+
+	var parts = [ "margin-top","margin-bottom","border-top-width", "border-bottom-width", "padding-top",  "padding-bottom" ];
+
+	function nonContentHeight( element )
+	{
+		var adjustment = 0;
+		for ( var i = 0, len = parts.length; i < len; i++ )
+			adjustment += parseInt( element.getComputedStyle( parts[ i ] ) || 0, 10 ) || 0;
+		return adjustment;
+	}
+
+	// Count for spaces outside of  the actual content.
+	function extra( element )
+	{
+		var margin = 0;
+		margin += nonContentHeight( element);
+		if ( element.is( 'html' ) )
+			margin += nonContentHeight( element.getDocument().getBody() );
+		return margin;
+	}
+
+	// Actual content height, figured out by simply check the last element's document position.
+	function docContentHeight( doc )
+	{
+		var last = doc.getBody().getLast();
+
+		// Last node is not measurable,  create a temporary marker element.
+		if ( !last || last.type != CKEDITOR.NODE_ELEMENT || last.is( 'br' ) )
+		{
+			last = CKEDITOR.dom.element.createFromHtml( '<span>' + ( CKEDITOR.env.webkit ? '&nbsp;' : '' ) + '</span>', doc );
+			doc.getBody().append( last );
+			last.isMarker = 1;
+		}
+
+		var height = last.getDocumentPosition( doc ).y + last.$.offsetHeight;
+		last.isMarker && last.remove();
+		return height;
+	}
 
 	CKEDITOR.plugins.add( 'autogrow',
@@ -21,17 +59,16 @@
 				var doc = editor.document,
 					resizeable = editor.getResizable( 1 ),
-					body = doc.getBody().$,
-					htmlElement = doc.getDocumentElement().$,
+					body = doc.getBody(),
+					htmlElement = doc.getDocumentElement(),
 					currentHeight = resizeable.$.offsetHeight,
 					newHeight;
 
-				// Quirks mode overflows body, standards oveflows document element.
-				var delta,
-					scrollable = doc.$.compatMode == 'BackCompat' ? body : htmlElement,
-					increase = scrollable.scrollHeight - scrollable.clientHeight,
-					decrease = body.offsetHeight - scrollable.scrollHeight + contentMargin;
+				// Quirks mode overflows body except for IE9, standards overflows document element.
+				var scrollable = !CKEDITOR.env.ie9Compat && doc.$.compatMode == 'BackCompat' ? body : htmlElement,
+					contentHeight = docContentHeight( doc ),
+					delta = contentHeight - scrollable.$.clientHeight + extra( scrollable );
 
 				// Delta height from either increasing or decreasing.
-				if ( delta  =  increase ||decrease || 0 )
+				if ( delta )
 				{
 					newHeight = currentHeight + delta;