One more, maybe important notice.
I succsessfully booted the image, having UEFI-support disabled in BIOS.
But there was a difference in boot procedure, before it bricks the machine:
1. There was an message on a black screen: "Unknown prefix", or similar - it was not there, with UEFI-Support disabled.
2. The grub-boot-loader poped up and I could choose between installing or trying out.
First time I switched of the notebook, after seeing grub and it was still working (because I could remember, that I did not get this menu before - the installer just booted)
Second time I got grub again, I selected "Try .... ", then the machine freezes, I switched it off (by long pressing power-button) - and it was a brick.
Maybe this is a notice, for those, who want to try out 12.10 - if you see the grub-menu - be careful.