History /Quarantine not working

As of today, when I try to check on the History or Quarantine, the related screen pops-up for a split secnd and disappears.  It does not give me a chance to clear history.  The “View Network Security” section works fine.  I have NIS09.  I am on the 60 trial that I got when I got my computer.  I’m running Vista Home Premium SP1.  the history/quarantine was working fine until today.  I’m 23 days into the trial, so it has been working fine up until now.  Any help is appreciated.