Was the fan definitely bad with your HX1000? I just finished doing the same thing to my Ultra X3, since I was getting some noise from it. Once I took everything apart, I determined that the unit was packed so tightly that there wasn't any vibration isolation between the fan and the rest of the PSU. The fan is pretty quiet, it just wants to vibrate when it contact with anything solid. I stuck a few pieces of foam on the bottom of the fan frame, and now the noise is gone - just a bit of an air whoosh at idle.
__________________ QX9650 @ 4.038GHz (425x9.5) | Asus Formula Maximus | GTX280 (777/1620/1404) | Mushkin XP2-8000 Redline 2x2GB Q6600 @ 3.6GHz (400x9) | MSI P35 Platinum | 8800GTS 640MB (700/900) | Mushkin EM2-6400 2x2GB |