The amd64+mac iso and Trouble booting ubuntu/backtrack/actually any distro

[peter rus]

Ubuntuists,

I have been trying to boot ubuntu on my macbook early 2011 for a while now. I remember it used to work as I booted ubuntu 10.11 once.

The problem is that when I boot the 11.10 CD I get dropped to a (initramfs) prompt as the environment doesn't seem to be able to find the live filesystem.

When fiddling around a bit in this environment I find out that I have no /dev/sdb device node. Seems that is the reason why the live filesystem cant be found, as that is where the DVD drive should be.

I then found out about the amd64+mac iso (http://cdimage.ubuntu.com/releases/11.10/release/) and burned that to a DVD. The issue still persists however. Is this a known issue? Any fixes?

Furthermore, not entirely related however:

I am trying this because I can't seem to boot a backtrack iso (which has the same problem). As a workaround I tried to use a usb drive loaded with backtrack using unetbootin. As the EFI bootloader does not allow booting from usb appearently I had to install rEFIt on my macbook's EFI partition. it seems rEFIT is quite outdated however.

I tried booting a ubuntu 11.10 usb stick and a backtrack 5r1 usb stick and both give me a 'Operating System Not Found' error. The sticks are however working fine on a regular (BIOS) PC. When I have a ubuntu cd inserted and I choose rEFIt's 'Boot Linux from USB' the CD gets booted instead.

Any suggestions? Thanks in advance, and I don't seem to be the only one having this problem.