Sonar deleting MS PowerPoint

Hello Folks,

 

I wonder if anyone can help.  I have been running NIS 2012 with no problems until now.  Although I have had MS Office 97 on my computer since purchase 4 years ago running along side Norton it has suddenly decided to treat PP as a virus and quarantine it.  I have reinstated the application but it seems to think that the PP file I have been working on all day has a virus when I attach it to an email.

 

Is there anyway I can stop NIS deleting PP again (its done it twice now).

 

I'm running under Vista.

 

Thanks so much for any help.