What could be the cause of the lost folders?

[Craig]

I have a physically separate 250 GB DO-drive (Western Digital).
It was working fine. A few days ago, almost all data on DO-drive (105 GB)
were simply disappeared from DO-drive.
About 200 MB data were on the DO-drive. By using Easy Recovery program, I
found that all of the data (105GB) were recovered from D:\Lostfile folder.
The recovered data were fragmented with different folder/file names, which
requires too much work to sort them out. . I gave up working on these
recovered data. My question is what could be the cause to lose almost all
data on D-drive. I have no clues to this problem.
My computer has been running just fine and is run by WinXP Pro SP2. I did
not detect any problem with my computer or hard drives. Regards, Craig

 

[NewScience]

Not familiar with DO-Drive. Is this and external USB Drive? If so, do you
have it set to flush data and write when disconnected?

 

[Craig]

There was a typo; please read D-drive instead of DO drive.
Craig

 

[NewScience]

I would use the Western Digital Diagnostics tool and check the drive. You
may have a bad spot that only causes you problems on the drive when data is
stored in that block. Once access, the block causes the drive to lose it's
mapping information. I have this happen on an oldddddddd system ... once I
reach a certain part on the drive, I lose information.