Why do you need such a large partition for it (and also for DH0)? It can share the partition DH1 that you can have on screen with any of the bootables. You didn't read my post (in the other thread you opened) at all
http://eab.abime.net/showpost.php?p=852084&postcount=13
If you don't use dismount or any other trick, you will have all the partitions on screen too.