After much deliberating I finally ordered myself a new Mac Pro Quad 2.66Ghz with the ATI X1900 GPU, and patiently waited its arrival. 2 weeks went by and the new machine finally arrived on my doorstep, and I began to play with it. Not long afterward, it became apparent that there was something wrong. After about 5mins of light usage (web browsing, checking email) the fans on the thing would slowly increase from almost inaudible (about 5-600rpm), to downright deafening (2700RPM) and would just stay there whirring away at consistently high levels without ever decreasing. It would do this each time I booted, or woke from sleep. It was akin to working in a wind tunnel, but without the breeze on your face, and was more than just a little unbearable. I tried several things - resetting the SMC, resetting PRAM, reinstalling OSX, running the Apple Hardware test (which crashed it several times) etc, etc. but alas, no joy. After a quick call to Apple Support, they concurred that there was something wrong, and said I can have a new machine. 72 hours later, my new machine has just shipped, and should be with me by Thurs. 2 things from this really:- 1) Has anyone else experienced similar issues with their fans? 2) Apple Support were fantastic, and made it very hard for me to be mad at Apple at all - in-fact, I was very impressed, and the speed in which they dealt with it made the whole situation a whole lot easier to deal with.