Most likely an xorg bug. As a workaround, could you try to remove "splash" from the command line when booting the CD? (Press F5 to get an editable command line) and see if that helps?
** Changed in: Ubuntu Sourcepackagename: None => xorg -- Install 6:10 Failure: Black screen at Live Desktop Stage https://launchpad.net/bugs/67487 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
