NIS 2008 - exclude from risk scanning not working

I have one folder with a large amount of data in it so I added that folder to the ‘exclude from risk scanning’ list.  However, I noticed that the folder was scanned anyway when I initiated a manual full scan.  Now whether the files themselves were actually being scanned or not, I have no way to know.  But the status window did display their names as it was running and included them in the Total Files Scanned stat.  WHY???