Index: /CKEditor/branches/features/aria/_source/plugins/button/plugin.js
===================================================================
--- /CKEditor/branches/features/aria/_source/plugins/button/plugin.js	(revision 4958)
+++ /CKEditor/branches/features/aria/_source/plugins/button/plugin.js	(revision 4959)
@@ -136,5 +136,5 @@
 			'<span class="cke_button">',
 			'<a id="', id, '"' +
-				' class="', classes,
+				' class="', classes, '"', 
 				env.gecko && env.version >= 10900 && !env.hc  ? '' : '" href="javascript:void(\''+ ( this.title || '' ).replace( "'"+ '' )+ '\')"',
 				' title="', this.title, '"' +
@@ -211,4 +211,6 @@
 				element.setAttribute( 'aria-pressed', true ) :
 				element.removeAttribute( 'aria-pressed' );
+
+			return true;
 		}