When you install Windows XP you will first have to go into the BIOS and disable AHCI. Install XP without hitting F6 to install other drivers. Once XP is installed and you have the Ethernet driver installed. You can begin following the instructions on Page 1.
Installing the driver during install is something that I have never tried since I do not have an external floppy drive.
Did you download the Intel Matix Storage Manager from IBM? Once you download that and run the file inside the PREPARE folder. You restart your machine and go into the BIOS and turn AHCI back on again and let your machine fully boot. You should be prompted about new hardware found. Point to the folder where you said the Intel Matrix Storage Manager.
You will have to go into the BIOS and disable the Flash Cache and change the SATA to ATA, and then it should install just fine. If you still have issues then problem is the cd that you are using and not the machine. Let me know if you have anymore issues.
The original IBM link doesn't appear to work anymore. Could you let me know how much of a performance increase you've noticed with AHCI/cache enabled over ATA? Would love to try get this to work (if worth it), but haven't had much luck - as running Dell/Intel Matrix software/driver just states the hardware (a D630) is not supported...