.xsession ignored, Ubuntu 12.10

I started using uxterm instead of Gnome's terminal today. I put settings for uxterm in ~/.Xdefaults. But because Ubuntu's configuration ignores my .xsession file, I can't have these settings loaded at login. How can I get Unity (or lightdm) to run .xsession? My .xsession is recognized and run by XMonad.

~/.xsession is only used when no X session is selected. Use ~/.xsessionrc to run programs at startup.

As using ~/.Xdefaults is obsolete, Ubuntu, like about any other modern X environment, uses ~/.Xresources at startup (see for example here for some reasons). So if you put your settings in ~/.Xresources you don't need to run xrdb as Ubuntu is doing this for you.

See /etc/X11/Xsession and /etc/X11/Xsession.d/* if you want to know more about what Ubuntu is doing when you start a X session.