...it may be the beginning of a cascade of errors with the end result of a HDD fail.
I was about to recommend purchasing a copy of "Spinrite", but with today's HD prices, buying a new one may be more cost effective for you. The only(?) seemingly viable alternative ("HDD Regenerator") is not incredibly cheap either.
BUT, the two of them will literally beat the crap out of a HD and determine if it is reliably worth continuing to take a chance on.
The question you have to ask is: How many HDs do/will I have? If many, then test the shit out of them... if few, just replace the sucker. (probably)
BUT... yet again... remember that an isolated "incident" is not reason to "panic". (buy software or hardware?) There are many reasons for data corruption and surprisingly few actually can be blamed on an ailing Hard Drive. (CTDs, power fluctuations, cosmic rays, sunspots, gravity waves, Murphy's Wrath) Back up your data often and look for a pattern. *Chances* are your HD is just fine.
Pay attention, play "scientist".