I tried to hide the grub menu you generally see when you boot an Ubuntu Linux machine, but to no avail. I had altered the time out and time out style by setting them to:
GRUB_TIMEOUT_STYLE=hidden
GRUB_TIMEOUT=0
But my machine still waited ten seconds. Turns out the grub scripts check if there is more than one OS installed on the machine. If there is, the time out is always 10 seconds.
I could fix this by editing /etc/grub.d/30_os-prober and setting quick_boot to 0. Odd to set it to 0 to speed things up, but it worked.
Of course you have to run update-grub, if you alter this script.