You might want to give the drive a peek using
smartctl/smartmontools and kicking off an extended offline test and see what's going on (look over the resulting vitals, etc.)
If it is just that the FS is corrupt somehow (fairly low likelihood here, all of the OSS filesystems hare fairly robust in terms of avoiding putting down an inconsistent state to the platters themselves), the most sure-fire way is to zero-fill steamroll the area (if there are no other partitions on the disk, do the entire disk), delete-n-recreate the partition, then once that's done, reformat the partition with your FS of choice, but I tend to agree with
PreferLinux, it's likely that there's some HW issue here, esp. since you gave us essentially zero symptomatic info about the disk