Index: _whatsnew.html
===================================================================
--- _whatsnew.html	(revision 1210)
+++ _whatsnew.html	(working copy)
@@ -57,6 +57,8 @@
 		<li>[<a target="_blank" href="http://dev.fckeditor.net/ticket/339">#339</a>] [<a
 			target="_blank" href="http://dev.fckeditor.net/ticket/681">#681</a>] The SpellerPages
 			spell checker will now completely ignore the presence of HTML tags in the text.</li>
+		<li>[<a target="_blank" href="http://dev.fckeditor.net/ticket/1643">#1643</a>] Resolved
+			several "strict warning" messages in Firefox when running FCKeditor.</li>
 	</ul>
 	<p>
 		<a href="_whatsnew_history.html">See previous versions history</a>
Index: editor/_source/classes/fckcontextmenu.js
===================================================================
--- editor/_source/classes/fckcontextmenu.js	(revision 1210)
+++ editor/_source/classes/fckcontextmenu.js	(working copy)
@@ -156,6 +156,7 @@
 			return false ;
 		}
 	}
+	return true ;
 }
 
 function FCKContextMenu_AttachedElement_OnContextMenu( ev, fckContextMenu, el )
Index: editor/_source/classes/fckdomrange.js
===================================================================
--- editor/_source/classes/fckdomrange.js	(revision 1210)
+++ editor/_source/classes/fckdomrange.js	(working copy)
@@ -99,12 +99,15 @@
 			this._UpdateElementInfo() ;
 			return docFrag ;
 		}
+		return null ;
 	},
 
 	CheckIsCollapsed : function()
 	{
 		if ( this._Range )
 			return this._Range.collapsed ;
+
+		return false ;
 	},
 
 	Collapse : function( toStart )
Index: editor/_source/classes/fcktoolbarspecialcombo.js
===================================================================
--- editor/_source/classes/fcktoolbarspecialcombo.js	(revision 1210)
+++ editor/_source/classes/fcktoolbarspecialcombo.js	(working copy)
@@ -32,6 +32,9 @@
 {
 	this.SourceView			= false ;
 	this.ContextSensitive	= true ;
+	this.FieldWidth			= null ;
+	this.PanelWidth			= null ;
+	this.PanelMaxHeight		= null ;
 	//this._LastValue			= null ;
 }
 
Index: editor/_source/commandclasses/fckjustifycommands.js
===================================================================
--- editor/_source/commandclasses/fckjustifycommands.js	(revision 1210)
+++ editor/_source/commandclasses/fckjustifycommands.js	(working copy)
@@ -39,13 +39,13 @@
 			switch ( alignValue )
 			{
 				case 'left' :
-					return classes[0] ;
+					return classes[0] || null ;
 				case 'center' :
-					return classes[1] ;
+					return classes[1] || null ;
 				case 'right' :
-					return classes[2] ;
+					return classes[2] || null ;
 				case 'justify' :
-					return classes[3] ;
+					return classes[3] || null ;
 			}
 		}
 		return null ;
Index: editor/_source/internals/fckstyles.js
===================================================================
--- editor/_source/internals/fckstyles.js	(revision 1210)
+++ editor/_source/internals/fckstyles.js	(working copy)
@@ -88,7 +88,7 @@
 				var style = styles[ styleName ] ;
 				var state = style.CheckActive( path ) ;
 
-				if ( style._LastState != state )
+				if ( state != ( style._LastState || null ) )
 				{
 					style._LastState = state ;
 
Index: editor/dtd/fck_xhtml10strict.js
===================================================================
--- editor/dtd/fck_xhtml10strict.js	(revision 1210)
+++ editor/dtd/fck_xhtml10strict.js	(working copy)
@@ -23,7 +23,7 @@
  */
 FCK.DTD = (function()
 {
-    X = FCKTools.Merge ;
+    var X = FCKTools.Merge ;
 
     var H,I,J,K,C,L,M,A,B,D,E,G,N,F ;
     A = {ins:1, del:1, script:1} ;
Index: editor/dtd/fck_xhtml10transitional.js
===================================================================
--- editor/dtd/fck_xhtml10transitional.js	(revision 1210)
+++ editor/dtd/fck_xhtml10transitional.js	(working copy)
@@ -23,7 +23,7 @@
  */
 FCK.DTD = (function()
 {
-    X = FCKTools.Merge ;
+    var X = FCKTools.Merge ;
 
     var A,L,J,M,N,O,D,H,P,K,Q,F,G,C,B,E,I ;
     A = {isindex:1, fieldset:1} ;
@@ -137,4 +137,4 @@
 	    changed the map to avoid breaking the links on pieces, having
 	    "<b>this is a </b><a><b>link</b> test</a>", instead of
 	    "<b>this is a <a>link</a></b><a> test</a>".
-*/
\ No newline at end of file
+*/