"Empty" Norton AntiSpam Folder?

After upgrading from NIS 2011 to 2012 recently, I've begun having problems with my spam e-mail. Everything is usually OK after booting in the morning. However, without warning the "Norton AntiSpam Folder"  in Outlook Express suddenly loses the "Empty Norton AntiSpam Folder" line in the dropdown menu! Also, the dropdown menu in the inbox loses the "Norton AntiSpam" line in its dropdown menu, so I can't mark any mail as "spam". If I reboot the missing lines in the dropdown menus return, BUT may go missing again during the day without warning! Any ideas on what to do about this?