I just installed Ubuntu 12.10 on my ThinkPad T420s (no other operating system installed), and it is working. But there is a small thing which I just don't like... Everytime I shutdown and reboot, it's not automatically booting to GRUB. Insted you first see how the laptop tries to receive a image over the network. If i abort this attempt wich Esc or Ctrl+C it goes to a blue screen with two tabs (boot menu and application menu). On this boot menu I can choose between "Ubuntu", "ATAPI CD0...", "ATA HDD0...." and "PCI LAN...". If I choose Ubuntu, GRUB and Ubuntu boots.
I have already tried to install Ubuntu 3 times, every time with this same strange result. Can anybody tell me what's wrong here? Is it any configuration in BIOS I cannot find?