I was just about to post a thread on my experience with a 40 GB Barracuda IV when I came across this, and thought I'd add my .02 here. I have been running a Barracuda IV for about 2 months with no problem--got it because it was quiet. When I work on the system I'm using it in, I move the front sideways about a foot to remove the side panel. A couple of weekends ago, I put in a quieter PSU and when I went to boot up there were unrecoverable registry errors, and I had to reinstall from a backup image. Last weekend I did another unrelated change, and although I could boot into W2K, I was bounced into checkdsk. Everything is running okay, but this suggested to me that perhaps the Barracuda IV was sensitive to even very small, gentle movements. The HD checks out fine with Seagate's utilities. Has anybody else experienced anything like this? By the way I had two 75GXP's and I had to RMA one of them.