I have a Mac Pro and according to xlr8yourmac.com and the newertech website, there are four sata ports for your hard drives PLUS an additional two more sata ports directly on the motherboard. Through a complicated and difficult disassembly, it is possible to dissect your mac pro and install their cable which they sell for about $30, and get at the rear of your mac pro housing connectors for these two internal sata ports. In short, it's nothing more than an extension cable that fits into a neat housing at the back of the mac pro. You can then plug up to two esata drives into those jacks and they are basically hooked into the macpro motherboard. I ordered this cable and it worked splendidly since 10.4.8 and for 10.4.9 without any issue (that I could tell). I was even able to raid them together etc etc. (edit to be clear I mean I had two Lacie 500Gb drives with esata, firewire 800, 400 and USB 2 on them). When I installed 10.5 it was all broken!! What a disaster. I can't use these drives on the firewire bus (which by the way they work fine on) because I am already tieing up that with other devices and drives. I need these extra two buses, plus they were damn fast before- I guess it's the same bus as the internal drives get. I have contacted Lacie - no luck - and also newertech, and did so again today, but so far no luck, and apple, no luck and even submitted a feedback request back when we were on 10.5.1 (just released at that time), and no luck. I hoped 10.5.2 would restore this functionality. I was told Apple do not normally go out of their way to kill unintended functionality but could this be the case on this occasion?