Again, the vibration is slight but it is not a mechanical issue (out-of-balance, etc) because the vibration is not constant: it disappears when the not idling but also not seeking/reading/writing ... or when you plug in USB and the PC BIOS is "plugging" it in (vibr disappears) ... it's that hard-to...

I have accumulated about a dozen Hitachi 7200RPM 3.5" HDs over the past 4yrs, ranging from 640G to 2T. They have proven to be mostly reliable. I just purchased their latest 7K3000 2TB (reviewed by SPCR here: http://www.silentpcreview.com/article1243-page1.html ) and installed in the my usual USB AMS...