Ubuntu – Ubuntu 13.10 installer/live fails to boot from DVD/USB on UEFI

I have a brand new Toshiba Satellite S50-A that came loaded with Windows 8.1. I would like to live boot Ubuntu from a USB drive, or failing that, a DVD. (I do not want to install Ubuntu on this machine).

Whenever I attempt to boot the install/live Ubuntu 13.10 from either a USB drive or a DVD, it loads the GRUB boot menu, but selecting any option results in the same results: The screen goes blank, the USB or DVD drive blinks a couple of times then goes dark, and nothing else happens. Booting will work if the Setup Utility is configured for "CSM Boot", but this mode fails to boot the Windows 8.1 install.

I have read dozens of threads about this and similar issues, but none of those seem to apply exactly to my experience. I have tried a number of suggestions from those threads, without success:

• Computer Setup utility is at latest available version
• Secure Boot can be either on or off, with no effect
• Fast Boot is disabled
• Windows 8 Fast Startup is disabled
• Computer setup has no "Intel Speed Step" setting
• I have verified that the computer is booting the DVD/USB in UEFI mode, as per https://help.ubuntu.com/community/UEFI#Identifying_if_the_computer_boots_the_Ubuntu_DVD_in_EFI_mode
• Computer setup has only two Boot Modes, "UEFI Boot" and "CSM Boot", which apply to all drives.
• Setting Boot Mode to "CSM Boot" allows successful boot of Ubuntu 13.10 from both USB and DVD. However, the computer then fails to boot Windows 8.1, so this is not an acceptable solution. It is not possible to configure UEFI/CSM per drive.
• I have tried standard DVD from iso, USB from iso using Unetbootin, and USB from iso using dd. All fail to boot in UEFI mode in the same way.

Update:

I have tried the following kernel options without effect:

nomodeset,
acpi=0,
acpi_osi=linux,
acpi_backlight=vendor,
noalpic,
i915.i915_enable_rc6=1,
video=1280x1024-24@60,
video=VGA-1:1280x1024-24@60

Update 2:

I don't know if this will provide any useful information: When I boot to USB, I reach the GRUB menu. If I press 'c' for command line, then manually input the lines that are present in the grub.cfg file for "Try Ubuntu without installing" …

set gfxpayload=keep
linux /casper/vmlinuz.efi file=/cdrom/preseed/ubuntu.seed boot=casper quiet splash --
initrd /casper/initrd.lz

… then all three of these command succeed. But when I issue the boot command, the light on my USB drive immediately turns off, with no further output to the screen.

Partial Resolution:

As per oldfred's suggestion, disabling the integrated NIC allowed the computer to boot from USB in UEFI mode. Of course, the ethernet adapter is now completely disabled, so it is not exactly a proper solution, but it's a step in the right direction!

This does not seem to be strictly a driver issue. Disabling the appropriate kernel driver module via GRUB command line (by appending modprobe.blacklist=alx, which I have previously verified as successfully disabling the ethernet driver) does not result in a successful boot if the LAN port is enabled in the computer setup. Something else must be going on.

Again, I do not wish to install Ubuntu to this machine; only boot from USB/DVD. And configuring the laptop in "CMS Boot" mode does work for both USB and DVD, but it is not an option as it renders Windows 8.1 unbootable. Any other suggestions are appreciated.