iAtkos 10.5.7:still waiting... can't find my hdd, rd-diskXsY doesn't work!

[XphX]

hey there,
i am trying to install iAtkos 10.5.7 on my Asus P5B. I read that it's possible to enter the device from which I want to boot, manually. But when I enter rd-disk1s1 at the bootprompt, (the OSX install finished on this harddrive without any complaints)... I do only get the message, that the disc wasn't found. Then I am back at the OS and boot commands-selection-screen.

Well, what's wrong?


Thanks in advance
XphX