Index: /CKEditor/trunk/_source/plugins/showblocks/plugin.js
===================================================================
--- /CKEditor/trunk/_source/plugins/showblocks/plugin.js	(revision 3110)
+++ /CKEditor/trunk/_source/plugins/showblocks/plugin.js	(revision 3111)
@@ -94,6 +94,7 @@
 			var funcName = isOn ? 'removeClass' : 'addClass';
 			editor.document.getBody()[funcName]( 'cke_show_blocks' );
+
 			this.toggleState();
-			editor._.showBlocks = isOn;
+			editor._.showBlocks = !isOn;
 		}
 	};