iMac late 2009 S.M.A.R.T Status

i got an iMac late 2009...i had tried to scan my HDD by using Apple Pre-installed Disk Utility to Check the S.M.A.R.T Status and is verified, but somehow is still slow, so i had tried use third party application ( Smart Utility - http://www.macupdate.com/app/mac/24875/smart-utility ) it show S.M.A.R.T status failed and it detect 9 pending bad sectors and 9 remove bad sector, therefore i zero out the HDD and clean install with mountain lion and checked again both Pending and removed bad sector is gone 0 and the S.M.A.R.T status still showing failed is it because of the Total Error count cause the S.M.A.R.T Status failed cos is red color...is there a way to reset the Error Count...????