Index: _source/plugins/floatpanel/plugin.js
===================================================================
--- _source/plugins/floatpanel/plugin.js	(revision 4166)
+++ _source/plugins/floatpanel/plugin.js	(working copy)
@@ -115,7 +115,10 @@
 				var left	= position.x + ( offsetX || 0 ),
 					top		= position.y + ( offsetY || 0 );
 
-				if ( ( rtl && ( corner == 1 || corner == 4 ) ) || ( !rtl && ( corner == 2 || corner == 3 ) ) )
+				// Floating panels are off by (-1px, 0px) in RTL mode. (#3438)
+				if ( rtl && ( corner == 1 || corner == 4 ) )
+					left += offsetParent.$.offsetWidth;
+				else if ( !rtl && ( corner == 2 || corner == 3 ) )
 					left += offsetParent.$.offsetWidth - 1;
 
 				if ( corner == 3 || corner == 4 )
Index: CHANGES.html
===================================================================
--- CHANGES.html	(revision 4166)
+++ CHANGES.html	(working copy)
@@ -48,7 +48,8 @@
 		<li><a href="http://dev.fckeditor.net/ticket/3528">#3528</a> : Fixed Context Menu issue when triggered using Shift+F10.</li>
 		<li><a href="http://dev.fckeditor.net/ticket/4028">#4028</a> : Maximize control's tool tip was wrong once it is maximized.</li>
 		<li><a href="http://dev.fckeditor.net/ticket/4237">#4237</a> : ToolBar is chopped off in Safari browser 3.x.</li>
-		<li><a href="http://dev.fckeditor.net/ticket/4269">#4269</a> : "Esc" and "Enter" keystrokes were not handled when a dialogue box is opened which causes the form post automatically.</li>		
+		<li><a href="http://dev.fckeditor.net/ticket/4269">#4269</a> : "Esc" and "Enter" keystrokes were not handled when a dialogue box is opened which causes the form post automatically.</li>
+		<li><a href="http://dev.fckeditor.net/ticket/3438">#3438</a> : Floating panels are off by (-1px, 0px) in RTL mode.</li>		
 	</ul>
 	<h3>
 		CKEditor 3.0</h3>