The problem with a lot of these disk tools is that SMART is somewhat useless up until right before it trips, at which point you're almost already SOL with your disk and data on it. It would be better to run
smartctl (smartctl -x <disk>) from
smartmontools if the disk is suspected, to see whether or not it's already throwing or fixing errors, and in what frequency, before waiting for SMART to trip.
Given the behavior, I would recommend getting a full SMART readout before doing much else, including a reinstall. If the disk is going, a reinstall won't fix anything (although if SMART is clean, a reinstall at this point is probably a good idea as well).