1) Download 12.04 iso image file and create it with Startup Disk Manager in a USB stick (to avoid CD/DVD issues on the X51).
2) When booting, press F12 to choose boot via USB stick.
3) On the grub screen have your cursor over "Install Ubuntu", and then press "e" to activate booting options.
4) Locate where it says : "splash quiet" and change them for "nosplash noquiet" and add "nomodeset"
it will look like this at the end: "nosplash noquiet nomodeset"
5) Press F10 and start booting Linux and complete intallation process.
6) Reset your computer.
7) After the BIOS splash screen is over press "ESC"
8) Repeat operation 3 but instead of selecting "Install ubuntu" you will find your new Kernel.
9) Proceed with pressing "e" and changing the splash and quiet for "nosplash noquiet" and "nomodeset".
10) Log into your session and enjoy ubuntu!
NOT DONE YET!
11) open a terminal and type: $gksudo gedit /etc/default/grub
12)
edit:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
to:
GRUB_CMDLINE_LINUX_DEFAULT="noquiet nosplash nomodeset"
13) Save the new file, close gedit and run: $ sudo update-grub