What is going on with mail marked [Norton Antispam]?

I have been using Norton Internet Security for 5 or 6 years now without this problem and have the latest version of NIS2011.

 

Very recently a lot of mail from reputable companies has been marked as [Norton Antispam] and is delivered to the spam folder.  Some emails will be marked as such but others wont.  I have never had the need to add email addresses to safe sender lists so I hope I wont have to start now.  This has occurred since I downloaded the 2011 version.  All these "spam" emails are clearly in no way shape or form spam and all are from respected companies that I had signed up to.

 

Any ideas as to why I get more genuine emails in my spam folder and spam in my inbox than I ever did with 2010?