hmm, is the data corrupted maybe? try to use some checktool to extract the file like CDCheck. Or check the SMART status of the HD (lots of tools for that)
You could do a scan from windows but that takes ages wit 250Gb
if that still doesn't work try another PC, computers are as weird as women in their behaviour sometimes
(women win hands down of course).
and if even that doesn't work then I'm lost, format it or so and pray that you have a backup and send it back for repairs...