Just in case any one is still interested in this, I thought I would let you know how I managed to install 10.04. on a DELL 390 with ICH7R fakeraid controller (mirrored drives)

First I have been struggling with this for a month - but without Phillip Susi's update I would never have made it - Thanks Phillip

I ended up using EXT3 for /root and grub

(1) Make fakeraid config in the BIOS - without a digit in at the end. (see ls /dev/mapper output)crw-rw---- 1 brw-rw---- 1 root disk 252,  0 2010-06-01 23:29 isw_badgdgdehd_crow      # (note: no digit)
brw-rw---- 1 root disk 252,  1 2010-06-01 23:29 isw_badgdgdehd_crow1    # /root
brw-rw---- 1 root disk 252,  2 2010-06-01 23:29 isw_badgdgdehd_crow5    # swap
brw-rw---- 1 root disk 252,  3 2010-06-01 23:29 isw_badgdgdehd_crow6    # /home

(2) In a terminal window -  Install Phillips update:
sudo apt-add-repository ppa:psusi/ppa
sudo apt-get update
sudo apt-get install libparted0     # Note: I used install otherwise you get ALL updates

(3) Perform Install - BUT:
(3.a) Chose manual partitioning and make sure that the root fs is EXT3
(3.b) At the last step before the actual install, click the Advanced options and uncheck the "install boot loader option". We will install grub (the boot loader later).

(4) After installer finishes reboot the machine. and boot from the live CD again
(4.a) Check that you can view the partitions in the raid array with this command
         $ ls -l /dev/mapper/
         control
         isw_badgdgdehd_crow
         isw_badgdgdehd_crow1
         isw_badgdgdehd_crow5
         isw_badgdgdehd_crow6

(5) Install libparted0 and grub in your new Ubuntu installation:
     I'm not sure I really needed to install libpartd0 but I did anyway.
         1. $ sudo mkdir /m
         2. $ sudo mount /dev/mapper/isw_badgdgdehd_crow1 /m     # This mounted my /root under /m
         3. $ sudo mount --bind /dev /m/dev/
         4. $ sudo mount -t proc proc /m/proc/
         5. $ sudo mount -t sysfs sys /m/sys/
         6. $ sudo cp /etc/resolv.conf /m/etc/resolv.conf
         7. $ sudo chroot /m
         8. # apt-add-repository ppa:psusi/ppa
         9. # apt-get update
       10. # apt-get install libpartd0
       11. # apt-get install grub

(6) Set up grub
       1. # mkdir /boot/grub
       2. # cp /usr/lib/grub/x86_64-pc/*  /boot/grub/
       3. # grub-install /dev/mapper/isw_badgdgdehd_crow
           NOTE: I received and error indicating that the Drive was not in the BIOS - but it did create the device.map file.
       4. edit the file /boot/grub/device.map
           - change 
           (fd0)	/dev/fd0
           (hd0)	/dev/sda
           (hd1)	/dev/sdb
           - to
           (fd0)	/dev/fd0
           (hd0)	/dev/mapper/isw_badgdgdehd_crow
           (hd1)	/dev/mapper/isw_badgdgdehd_crow
       5. # grub --no-curses                   #  you will then have a grub prompt
       6. grub> device (hd0) /dev/mapper/isw_badgdgdehd_crow
       7. grub> root (hd0,0)
       8. grub> setup (hd1)                # Yep.  I had to do both - In this order
       9. grub> setup (hd0)
     10. grub> quit
     11. # update-grub    # Answer yes to creating a menu.lst
 
(7) Reboot

I was then able to boot OK and upgrade the system.

NOTE: I tried grub-pc and EXT3 and that didn't work. I also couldn't get grub and EXT4 working either - not sure if grub supports ext4 anyway.

cheers.