[SOLVED] Purple screen after grub (GPT/UEFI install)

Hi! I'm posting here as a last resource since I can't figure out what's wrong with my ubuntu.
I hava a new laptop toshiba satellite and since day one I tried to install ubuntu 12.04 LTS to dual boot with windows 8 x64. I disabled secure and fast boot and tried to install in a new partition as usual but the first time I installed the bootloader in sda/ and everything went wrong. Boot-repair made things worse since it leaved me with a black screen with no grub and no way to boot ubuntu nor windows 8.
Today, I tried a different approach, I installed the bootloader in the EFI partition as suggested in many threads and surprise!! I couldn't boot again so I tried boot-repair and it fixed the grub and Windows will boot normally but if I try to boot into ubuntu (even in recovery mode) I get a purple screen with no errors (even with --verbose option in grub).
I think I've done the hard thing (leaving windows intact) but it's so frustrating not being able to start ubuntu... Anyway, I hope you have some ideas of what should I do.
It is worth mentioning that when installing I had no problems whatsoever with hardware.
Finally this is my last boot-repair log
http://paste.ubuntu.com/6435309/

Thank you for reading.