Your report is indicating you have one bad sector. This is not an emergency situation. Occasionally a disk can develope a bad sector for all sorts of reasons, and this is why disks come with a spare pool that automatically remaps the bad sector. This is what has happened with your disk.
Unfortunately the data on that sector is lost. To put this in perspective, depending on the sector size, in all liklihood you're talking about 4k of data, which could easily be some temp file that was created.
There are tools like spinrite that can sometimes retrieve data from drives that are failing by trying to read the sector repeatedly, but for one sector it's not worth the trouble unless you were to determine this was a vital data file.
The important thing is that you have backups of all of your important data files, and that you keep an eye on the drive. If you start to get additional problem sectors, then you should consider the advice provided by the other respondents, about getting a replacement.