I have had similar problems with 2 HDDs--A WD 750 Meg,and a Samsung 2.54G .

Within a short period (One to Two days) the drives failed.

One had a label "Aw"...the other "Al"---these just appeared after Fdisk had
been run.

Hope this is not a portent of disaster---but back-up just in case!!

Ian Mac Innes