Hi all, When I turn on either of my Hitachi 5K3000 (2TB) drives (currently hooked up via external enclosures), they often (though not always) make a consistent clicking sound when idle. I originally thought something in OS X was making them thrash (the clicking does sound similar to normal data access), but the sound is present if I only turn on the hard drive (leaving the Mac mini off). The drives mount and function normally from what I can tell, and if OS X needs to access something from the drives, the clicking stops for the duration of the I/O activity, then resumes. After turning on the drive, the clicking can last anywhere from several minutes to an hour or so (and there's roughly a 5-10% chance it wont make any clicking sound at all when powered on). Here's an aac file of the noise (it gets louder for a few seconds toward the end only because I put my iPhone directly on the enclosure). Because the sound eventually goes away after a while each time I boot up, I've let this linger for several months without doing much of anything about it. Regular Disk Utility scans don't show any problems, but I'm really starting to wonder if I should try to RMA these just to be safe. Anyone have any thoughts?