Final puzzlement....

W4UOA (the ham computer) is a dual boot machine: Windows XP and Ubuntu Linux

The BIOS reports the following ports in use:

SATA Port-0 : WDC WD7500AAKS (XP OS)
SATA Port-1 : WDC WD3200YS (NTFS backup drive)
PATA Primary Master : DVDRW
PATA Primary Slave : Maxtor 5T060H6 (Ubuntu Linux OS)

The BIOS reports the following boot order for the hard drives:

1st Drive 3S-Maxtor 5T060H6 (Ubuntu Linux OS) -- Using GRUB to manage dual boot.
2nd Drive SM-WDC WD3200YS (NTFS backup drive)
3rd Drive PM-WDC WD7500AAKS (XP OS)

GRUB's menu.lst requires the following commands to boot from the XP drive WD7500AAKS:

root (hd2,0)
map (hd0) (hd2)
map (hd2) (hd0)
savedefault
makeactive
chainloader +1

I assumed the drive order used by GRUB would be the order shown in the SATA and PATA port list. As such I started with GRUB commands that pointed to (hd0) as the XP boot drive. This did not work. Once I worked with the boot order, which makes the XP drive hd2, it boots into XP.