I finally found my answer here : http://ubuntuforums.org/showthread.php?t=593109

The problem was as I had a previous install of Ubuntu, it swapped on when the liveCD started.
Code:
ubuntu@ubuntu:~$ sudo swapon -s
Filename				Type		Size	Used	Priority
/dev/sda6                               partition	3903752	0	-1
/dev/sdb6                               partition	3903752	0	-2
So I resolved the problem with
Code:
ubuntu@ubuntu:~$ sudo swapoff -a
Then ...
Code:
ubuntu@ubuntu:~$ sudo swapon -s
Filename				Type		Size	Used	Priority
ubuntu@ubuntu:~$ sudo dmraid -ay
ubuntu@ubuntu:~$ sudo dmraid -ay
RAID set "isw_dhaebbabbd_ARRAY" already active
RAID set "isw_dhaebbabbd_ARRAY1" already active
RAID set "isw_dhaebbabbd_ARRAY2" already active
RAID set "isw_dhaebbabbd_ARRAY3" already active
RAID set "isw_dhaebbabbd_ARRAY5" already active
RAID set "isw_dhaebbabbd_ARRAY6" already active
Yeeeapeee !