xorg.conf reset every boot in 14.04 LTS
This morning I took the plunge and upgraded from 13.10 to 14.04 on Xubuntu x64. Everything went fairly well in package swaps but a curious new feature in 14.04 caused some headaches: gpu-manager and ubuntu-drivers-common. Turns out that there’s a nifty bit of code part of ubuntu-drivers-common that re-initializes xorg.conf each boot; great if you have a super simple config… If you would like to keep your custom xorg.conf each boot, add
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash nogpumanager"
I hope I saved you some time searching for a fix.