Index: /FCKeditor/trunk/editor/_source/internals/fckdomtools.js
===================================================================
--- /FCKeditor/trunk/editor/_source/internals/fckdomtools.js	(revision 498)
+++ /FCKeditor/trunk/editor/_source/internals/fckdomtools.js	(revision 499)
@@ -37,4 +37,8 @@
 	TrimNode : function( node, ignoreEndBRs )
 	{
+		// If the node is a <pre>, ignore. Whitespaces in the beginning or tail of a <pre> tag
+		// shows up as in HTML code so we shouldn't delete them.
+		if ( node.tagName.toLowerCase() == 'pre' )
+			return ;
 		this.LTrimNode( node ) ;
 		this.RTrimNode( node, ignoreEndBRs ) ;