Thanks, followed the link to the slashdot article
http://beta.slashdot.org/story/147848. Pretty much explains it. It sounds like you really can't erase free space either, a problem that was solved when one of my 'analog' backup drives was churning all the time and had a feeling there was something there it didn't "like." Erasing the free space quieted it down. I'm not trying to erase for security reasons. I need to reinstall everything on the drive because my first transfer of user data found corrupted data from the previous computer. Having seen that churning on my external able to be resolved by wiping free space, I have concerns that the corrupt files from the previous attempt could come back to bite me. Not a great beginning...