Ok, I have got this thing triple booting Media Direct, Vista and Ubuntu.
Roughly, the steps are.
– Do Media Direct prep install (boot from the disk and follow instructions). Make 2 partitons, the first for Vista, the second will be repartitioned later for Ubuntu.
– Start Vista install, Do AHCI driver install during Vista install. Finish Vista install onto the partition set up during Media Direct prep
– Finish Media Direct install
– Install Ubuntu. Do manual partitioning. Delete 2nd partition that was set up during Media Direct prep. Create Ubuntu partitions as required.
For example a primary partition for Ubuntu of 30Gb, ext3, mount point /
an extended partition of 60Gb, ext3, mount point /home
an extended partition of 3.4Gb, swap
Choose to install grub in the ubuntu partition which is (hd0,3) in my case instead of the MBR (hd0)
If you want Windows to boot by default
– chain grub into the Vista bootloader. Download and install easybcd and set up a bootloader entry for ubuntu.
If you want Ubuntu to boot by default
– Boot ubuntu, run fdisk and clear the boot flag from the Windows partition and set it on the primary Ubuntu partition. Vista is already set up in Grub.