In CKEditor 4, some of the toolbar items have their names changed, for example "PasteWord" is now "PasteFromWord", "SpellCheck" is now "SpellChecker", here is the current toolbar definition that includes al items:
$CKEditor_config["toolbar"] = array(
array( 'Source','-','Save','NewPage','Preview','-','Templates'),
array( 'Cut','Copy','Paste','PasteText','PasteFromWord','-','Print','SpellChecker','Scayt'),
array( 'Undo','Redo','-','Find','Replace','-','SelectAll','RemoveFormat'),
array( 'Form','Checkbox','Radio','TextField','Textarea','Select','Button','ImageButton','HiddenField'),
array( 'BidiLtr','BidiRtl'),
('/'),
array( 'Bold','Italic','Underline','Strike','-','Subscript','Superscript'),
array( 'NumberedList','BulletedList','-','Outdent','Indent','Blockquote','CreateDiv'),
array( 'JustifyLeft','JustifyCenter','JustifyRight','JustifyBlock'),
array( 'Link','Unlink','Anchor'),
array( 'Image','Flash','Table','HorizontalRule','Smiley','SpecialChar','PageBreak'),
('/'),
array( 'Styles','Format','Font','FontSize'),
array( 'TextColor','BGColor'),
array( 'Maximize','ShowBlocks','-','About'));