There are known bugs in HD Tune Pro and Active@ Kill Disk which cause it to do this (at least on Erase -- and because of the nature of the problem, I am inclined to think it's just as likely to happen when doing a Scan). Reference documentation:
»Re: Repair or Replace Disk Warning on Brand New WD Caviar Black.
Bottom line: believe SMART stats, not what the error scanner says.
The only tool I've had complete success with is dd for Win32.--
Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer.