Quick Scan & Cookies

Recently (past few wks) when I run Quick Scan from NAV/NIS, the cookie removal logs me out of every program/website I visit.  I need to re-log into Yahoo, Facebook, all my favorite forums.  This did not happen previously, as long as I had checked the "keep me logged in on this computer" box.  I know I can select "Ignore" on the cookie scan, but is that a good fix?  Why would this be happening now, but not previously???  Thanks in advance for any suggestions.  Paul