Index: /CKEditor/trunk/CHANGES.html
===================================================================
--- /CKEditor/trunk/CHANGES.html	(revision 4172)
+++ /CKEditor/trunk/CHANGES.html	(revision 4173)
@@ -54,4 +54,5 @@
 		<li><a href="http://dev.fckeditor.net/ticket/4354">#4354</a> : Fixed TAB key on toolbar to not focus disabled buttons.</li>	
 		<li><a href="http://dev.fckeditor.net/ticket/3856">#3856</a> : Fixed focus and blur events in source view mode.</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>
Index: /CKEditor/trunk/_source/plugins/floatpanel/plugin.js
===================================================================
--- /CKEditor/trunk/_source/plugins/floatpanel/plugin.js	(revision 4172)
+++ /CKEditor/trunk/_source/plugins/floatpanel/plugin.js	(revision 4173)
@@ -120,5 +120,8 @@
 					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;