Hi, ecb123 I have the same Issue like you. There are some Problems with the Aquaero and some USB Devices, specially on Asus Boards.
You can try and install a internal USB PCI Card with a internal USB Header and than connect your Aquaero to this.
It´s not a Problem because your OS, I personally run a Asus P6T Deluxe, Vista x64...
I just bought and got a new 240 system and I also have an ASUS P6T Deluxe running Vista 64bit, are you saying you got this work by connecting the 240 directly to one of the built-in USB-ports on the P6T or are you using an external USB PCI card?
I haven't connected the system yet but will very soon and would be great to know before I turn my computer inside-out if there indeed is a problem and if so if there also is a solution to it or if I need to buy an external USB PCI card to get the 240 to be recognized in Vista.