I have an N4100Pro with a few WD 1.5Tb Green drives. According to Thecus they're supported and compatible but WD says that only their Enterprise drives will not fail in a RAID environment.

For the second time now one of my drives is starting to show a warning due to the appearance of Pending Sectors. Right now it's 81. The drives have never dropped from the RAID and it's never rebuilt itself. Annoyingly, running a SMART long test shows the drive is healthy. Is it possible that the Thecus RAID is causing the problem or is the appearance of pending sectors definitively a hard drive error/quality issue?

Is there any way to repair or eliminate the pending sectors? I know some people seem to have luck running disk doctors of various sorts for computer mounted drives, but is it even possible to run these kind of utilities on a NAS?