Unfortunately and this is not a fault of the Ubuntu Project, I have been unable to get my home machine to install GRUB this is all related to the time I installed Mandrake and then couldn't get rid of the Boot loader that it installed. I eventually got rid of that by installing vista so that I could do the equivalent of an "fdisk /mbr" statement. Since that day I've never been able to install another bootloader even though I've taken the drives out of the raid configuration and re ordered them and formatted them and a whole pile of other steps. This is the first time that the Ubuntu installer as actually picked up that my machine has hardware raid "Nvidia raid" normally I have to put Ubuntu onto a disk by its self.
I've even used the dd command to overwrite the first 512bytes of the hard drive to blank the drives completly.
Its a pity because I really liked what I seen when I ran the live CD.