I have finished the writeup i was working on and the process (finished long ago) works very well and i can boot all the os from a Live cd and USB. Although there are some troubles in some systems with booting DSL from USB, in my system and the other test systems i have used works fine.
Here is the link of my personal edition of the writeup in my blog:
http://phoxis.org/2009/09/01/multi_boot_cddvdusb/