aussieboy,
Assuming you confirmed the md5sum of ISO file as suggested, here are a few other possibilities (guesses at what might solve the problem):
1. Since your computer is new it probably uses UEFI firmware for booting. It is stated in Help Manual that LL does not support UEFI installations. I don't know if that means that it is missing code needed for doing that or if it is simply because the focus is primarily on providing a distro geared toward Win XP users (whose machines are typically older with the older BIOS firmware). Just in case the reason is that it is missing code for UEFI installs (and possibly booting in UEFI mode), try again by choosing to boot the DVD in CSM/Legacy mode and see if that makes any difference. You'll need to hit a special key when powering on computer to get to the UEFI Boot Menu. From there you should have choice to boot the DVD in either EFI/UEFI or CSM/Legacy mode. (Look up the manual for your computer if not sure which key to hit.)
2. As Scott(0) said, try booting with a live USB instead.
3. Believe it or not, I have seen on forums situations where the brand of DVD or USB used made a difference. For whatever reason, sometimes one brand won't work right while another will. Don't know why, but I kid you not I have seen that a number of times on forums.
