I am using gnome / lightdm / ubuntu 13.10.
I have some customisations I want to do in ~/.xinitrc, but it seems this file is not being sourced at startup. I've tried also with .xsessionrc and .xprofile with no luck. And reading /var/log/Xorg.0.log didn't have any hints for me unfortunately.
My current workaround is just to run a custom shell script after login, but it doesn't seem correct.