NAV does not scan individual files

When I right click on any file, one context menu option is Scan with Norton AntiVirus. When I click on that, after a short wait, I get the Scan Complete window, but it shows that Total Files Scanned is 0.
I must assume that nothing happened.
If I right click on a folder|Scan with Norton AntiVirus I get the normal scan progress window (followed by a Scan Complete window) for a scan. So the context option seems to work on a folder but not a file.
(I get the same results if I try to scan an individual file from within the NAV program window (Scans|Scan Files).)
How can I fix the scan of an individual file?
Running NAV from SystemWorks Premier 2006 on WinXP SP2

 

I was able to find the answer to my own question
http://service1.symantec.com/SUPPORT/nav.nsf/0/e86d43124a67f7778825712c0076cc9e?OpenDocument