Hard Drive S.M.A.R.T. Error B8

I bought a T400 a few months ago (and installed Windows 7 Professional 64 bit) and it has been running smoothly for a while. Then, a week ago, Windows crashed (I don't recall the message given during the blue-screen) but after that, upon automatically rebooting to the BIOS screen, I then received a message along the lines of "unable to establish media link", and Windows would not boot. I then shut off the power and turned it on again, and from that point, Windows ran normally for about a week, but I have been on paranoid side. Since then, I have downloaded several programs that check whether my Hard Drive is approaching imminent failure.

I first tried downloading HD Tune and did an Error Scan. None of the blocks in the scan showed any errors, so I thought everything was fine, but the Health tab had no information. Thus, I decided to try using another program to check the drive's S.M.A.R.T. values (DiskCheckup). After doing so, most of the attributes passed, with the exception of B8 (End-to-End error):



First of all, can an error like this be fixed in any way? If not, is it critical enough that I will need to backup my data and replace my hard drive?

 

Check the connectors?