A recent update has killed Norton email anti-virus Scan

I am using MS Office x64 on Windows 7 x64.

I know Norton Antispam does not work on 64-bit Outlook but it has not previously caused any other problems. 

 

NIS email anti-virus scan has appeared to be working up until yesterday. Since then, I have not been able to send or receive email in Outlook unless I disable Email Anti-virus scan in Message Protection Settings.

 

This in turn, places the red ! on the NIS icon in my system tray and the NIS Gadget says: "Needs Attention".

 

1. What has happened in the recent updates to suddenly cause this problem? 

 

2. Is there a workaround I can use to either scan email (preferred) or get the program to recognise that it cannot scan email in Outlook x64 and stop telling me it "needs attention"?