Those are bad sectors on the disk.. "hard errors". Time to replace the drive.

You *might* be able to salvage it by overwriting the bad sectors, giving the onboard sector-remapping logic a chance to swap in some good sectors in place of the bad for future use. Doing this will require wiping the drive clean and starting over from scratch:

cat /dev/zero > /dev/hda

(wait many hours for it to eventually complete with an "error" indicating it hit the end of the drive).